Need help making a decision on your project? Request a sample.

Working on a project? Request a sample.

McNICHOLS® Glossary

The McNICHOLS® Glossary will help you navigate product and industry-specific terms on our website. Product attributes and the qualities associated with them are further defined. The Glossary also includes details related to relevant classifications, standards, methods of measurement, and more. While we believe you will find our Glossary helpful, we are also ready to assist should you have any questions. Our Customer Support page highlights various ways we are available to serve you!




AASHTO stands for the American Association of State Highway and Transportation Officials. Many McNICHOLS products comply with construction requirements set forth by this organization.

Accessories are items typically used in conjunction with a primary product. They are often used to frame, stabilize, or attach the primary product to a structure. Items such as Angles, Carrier Plates, Fasteners, Flat Bars, Nosing and U-Edging are categorized as Accessories.

ADA Compliant refers to materials that fulfill the accessibility requirements for construction as set forth by the Americans with Disabilities Act. McNICHOLS offers several items that are ADA compliant in the Bar Grating, Fiberglass Grating, Plank Grating, and Decking & Flooring product categories.

AISI is the acronym for the American Iron and Steel Institute, which is a trade organization made up of North American Steel producers. AISI is an organization that supports the development of new Steel technologies, collects and distributes industry information, and advocates for public policies that protect and promote the North American Steel industry.

The term Alloy refers to the makeup of the metallic elements within a specified product. Aluminum, Brass, Bronze, and Copper are Alloys supplied by McNICHOLS.

Aluminum is the second most commonly used Metal in the world largely because of its high strength to weight ratio. Aluminum is lightweight, durable, flexible, and corrosion-resistant. McNICHOLS offers many Aluminum products including Perforated Metal, Expanded Metal, Wire Mesh, Bar Grating, Plank Grating, Designer Metals and more.

An Anchor is a type of Accessory used on Bar Grating, Plank Grating, and Fiberglass Grating products to secure the Grating to its supporting structure. See also, "Fasteners".

Anchor Blocks (also known as Weld Lugs) are pieces of metal, typically with bolt holes, that are welded between adjacent bearing bars, that create a secure tab for attaching the Grating to a support system.

Angle refers to an Accessory that is typically at or near 90-degrees and has either equal or unequal legs. Angles can be used to frame sheet products like Perforated Metal, Expanded Metal, and Wire Mesh. Angle is also a common component used with Bar Grating, Stair Treads and for forming a trench. In a trench application, Angle is referred to as Embed Angle.

Angle Leg Size refers to the width of the legs of an Angle. The legs of an Angle are either equal in size or unequal (are two different sizes).

Annealing is the process of heat-treating Steel above its re-crystallization temperature, then cooling it at a controlled rate. Its purpose is to reduce hardness and increase ductility and machinability of the metal.

Anodizing is a process that forms a protective, integral Aluminum Oxide coating on the surface of Aluminum items. This process protects against abrasion and corrosion while enhancing the material's appearance.

ASTM International is the American Society for Testing and Materials. It is an organization for issuing standard specifications on materials, including Metals and Alloys.

Austenitic describes Stainless Steel with non-magnetic properties. Austenitic Stainless Steel is highly resistant to corrosion due to its nickel content and increased levels of chromium. Austenitic Stainless Steels are hardened and strengthened through cold-working rather than heat treatment and have excellent ductility. The two most common grades are Type 304 and Type 316.

Balanced Stubs, also termed Equal Stubs, refers to cut Hole Products, specifically Grating and Wire Mesh products, where the bearing bars or wires have equal lengths remaining around the edges on opposite ends of a cut piece.

Banding, also referred to as Flat Bar, is Metal material that is often cut to length then welded to the ends of bearing bars. This is done to give the product a finished appearance as well as prevent the bearing bars from twisting or warping over time. Two Banding types are available based on the placement of the welds: Load Banding and Trim Banding. See "Load Banding" or "Trim Banding" for more information.

A Bar Bend is a Pipe, Tube or Bar with one or more bends made to a specific radius or radii.

Bar Bend Size is a type of measurement of a handrail component known as a "bar bend".

Bar Grating is a product made with a series of bearing bars that are welded, swage-locked, press-locked, or clinched together with perpendicular cross bars (except for Clinched Bar Grating) in order to form a panel. Bar Grating is a load-bearing product often used in applications such as platforms, walkways, catwalks, factory floors, and as Stair Treads.

Bar Grating Construction Type is a characteristic that identifies how the bearing bars in Bar Grating are attached to the cross bars. Construction can be Welded, Press Locked, Locked by Swaging, Riveted or Clinched.

Bar Grating Spacing (e.g. 19-W-4) refers to the industry specification for Bar Grating products. For example, the first number refers to the bearing bar spacing measured on center (19 = 19/16" or 1-3/16"), the letter refers to the construction type (W = welded), and the last number references the cross bar spacing measured on center (4 = 4").

Welded Bar Grating is available with the following surfaces:

  • Smooth- Standard Surface
  • Serrated- Serrations are cut into the Grating's bearing bar surface
  • GRIP TIGHT™ - Grit is bonded to the Grating surface. GRIP TIGHT™ surfaces provide slip resistance and are available by special order

Bar Interlocks are dovetail-shaped rods that are inserted into slots in the side channels of DIAMONDBACK® Extruded Interlocking Plank Grating and Flooring for the purpose of attaching two adjacent Planks together. This results in an uninterrupted surface that is locked into place without having to weld the Planks together.

Bar Width (also referred to as Bar Size) is the measurement of the material between the outer edge of one hole to the outer edge of the nearest adjacent hole in a Perforated Metal sheet or plate.

A Beam Flange is the width of the flange that forms the top and the bottom of a structural I-Beam.

Bearing Bar Color identifies the color of the bearing bars that are used in Rectangular Bar Grating and Pultruded Fiberglass Grating products.

The Bearing Bar Height, also known as bearing bar depth, is measured from the bottom of the bearing bar to the top surface.

Bearing Bar Shape is the characteristic used in Grating products to identify the shape of a bearing bar. Bar Grating bearing bars can have a Rectangular Bar, I-Bar, or T-Bar.

Bearing Bar Spacing is the distance from the center of one bearing bar to the center of the next adjacent bearing bar.

Bearing Bar Thickness, also known as Bearing Bar Width, is the measurement of distance between the left surface of the bearing bar to the right surface of the same bearing bar.

Bearing Bars make up the majority of a Bar Grating item. Bearing bars are positioned upright and side by side. They run the length of a panel and are held in place by perpendicular cross bars.

Bend Angle is the angle of the bend in an "Elbow" type of Handrail Component, expressed in degrees.

Bolt Size refers to the diameter and length of a bolt or stud.

Bolting Cloth is a group of industrial Wire Cloth (Wire Mesh) specifications for a Stainless Steel or Monel Woven - plain weave item with a square mesh pattern. Bolting Cloth wire diameters are lighter than mill grade specifications and typically have a high percentage of open area.

Expanded Metal is composed of strands and bonds. Bonds are where the strands intersect. In other words, the bond is where each diamond-shaped opening is connected with the next opening.

A Bond Shear (or Bond Cut) is the result of cutting Expanded Metal sheets to size so that the diamond-shaped openings are closed along the margins of the cut piece, eliminating prongs or jagged edges. Bond shearing is restricted by the spacing of the openings in the sheet (see Random Shearing).

Bottom Flange Spacing is the measurement between the bottom flanges of adjacent bearing bars in an I-Bar, T-Bar, or Wide T-Bar Pultruded Fiberglass or Bar Grating panel.

A Bracket (also known as a Handrail Bracket) is used in the attachment of railings to adjacent walls or similar mounting structures.

The Brinell Hardness Test is a standard method of measuring the hardness of materials. The smooth surface of a Metal product is subjected to indentation by a hardened Steel ball under pressure. The diameter of the indentation in the material’s surface is then measured by a microscope and the resulting hardness value is compared to a hardness chart or determined by a prescribed formula.

Bronze is a Metal Alloy made up of mostly of Copper and Tin. It is known for its durability and ductility. McNICHOLS offers many Bronze products including Wire Mesh and Designer Metals.

Bundle Size refers to the quantity and size of the components included in a product or item bundle.

To Calender is to pass Wire Cloth through a pair of rollers in order to reduce thickness or flatten intersections of wires and provide a smooth surface. Also called rolled.

Camber refers to a slight bow in the vertical plane of the Metal which can occur during manufacturing and results in an out-of-square condition.

A Cap is a Handrail Component used to finish off the end of a rail or top of a post.

Cap Height, in Handrail Components, is the height of the end cap as viewed in profile.

Cap Type describes the component used to cap the ends of Pipe or Tube used as railing or posts.

Carbon Steel, also known as Carbon Steel, is a Steel Alloy that is mostly made up of carbon. It is known for its high levels of durability, malleability, and ductility. McNICHOLS offers many Carbon Steel products including Perforated and Expanded Metal, Wire Mesh, Bar Grating, and more.

Carrier plates, also referred to as End Plates, are accessories used in the manufacture of Stair Treads. They are designed to fit the ends of various Bar Grating and Plank Grating products and are punched with a slot and a hole for secure mounting to stair stringers. Carrier Plates are sold in pairs.

Expanded Metal Catwalk is an economical solution for ramps, flooring, platforms, walkways, treads, and other applications requiring a lightweight product. It is easily installed as it is made to fit in typical catwalk widths. It is manufactured in the same patterns as Expanded Metal Grating, but the direction of the diamond (Long Way of Diamond) runs across the shorter dimension of the sheet to provide better strength and loading characteristics.

Centerline Radius describes the way Pipe or Tube bends at its centerline, and is expressed as the dimension of the radius of the curve, in inches.

Centerline to Wall Distance identifies the distance from the wall to the centerline of the Pipe or Tube as it rests on the saddle of the handrail bracket. This characteristic is used within the Product Line of Handrail Components.

A Channel is a structural shape produced with two legs typically set at 90 degrees against a plate.

Channel Depth, or Channel Height, identifies the depth, in inches, of the side channel for Plank Grating items. The term "depth" is used for downturned channels. For walkway, channel "height" describes the channel when it is upturned.

Channel Size is the depth of a channel, typically used in reference to the structural shape of a channel.

Channel Width is the width of a channel that is typically part of the structural shape of Plank Grating.

Chemical Resistance is the ability of a material to withstand against damage that can be caused by a chemical reaction.

Class 1 identifies a Cold Rolled Sheet or Coil that is intended for exposed applications where surface appearance is primary.

Class 2 identifies a Cold Rolled Sheet or Coil that is mainly used for unexposed applications and can have more surface blemishes.

Clear (Open) Spacing is the open spacing between Grating bearing bars. It can be measured as the difference between the bearing bar thickness and the bearing bar center-to-center spacing.

Clear Span is the length of unsupported Grating and is critical in determining a Grating's load characteristics. Grating supports typically have a foot or ledge on which the Grating rests. The part of the Grating resting on the support is not part of the Clear Span. For example, if a 36-inch long piece of Grating rests on two supports, each with a 3-inch ledge, the Clear Span would be 36 inches minus the part of the Grating resting on the ledge (which is a total of 6 inches). In this example, the Clear Span would be 30 inches.

Clinched (or Castable) Bar Grating is a series of rectangular bars that are clinched together in a hexagonal grid.

CLOSE MESH, also called GCM Series, is press-locked Bar Grating formed through a process in which the cross bars and rectangular bearing bars are forced together using tremendous hydraulic pressure. The result is a flush-top, durable Grating that provides excellent lateral support and a small open space between bearing bars.

Closed Cell refers to cut-to-size pieces of Fiberglass Grating that will be cut so that there are no partial grid members sticking out. Closed Cell can only be accomplished when the dimensions required match the dimensions of a closed cell cut precisely.

Coarse Mesh is Wire Cloth with mesh count of less than 30x30.

Coil refers to some flat items, particularly fine mesh products, that have been wound into rolls.

Cold Dipped Galvanizing refers to the process of painting a layer of zinc coating onto a piece of metal.

Cold Working refers to changing the structure and shape of Steel by applying stress at a low temperature. It is a room temperature rolling process often used after hot rolling to increase hardness, strength, dimensional accuracy and to provide a smoother, brighter finish.

The term Color is used to specify the finished color of select items. It is a characteristic used with Fiberglass Grating and Stair Treads, PVC Coated Wire Mesh, Fiberglass Structural Shapes, and Painted Bar Grating Products.

Commercial Quality Steel is Steel with a carbon limit at 0.15 max. The characteristics of Commercial Quality Steel are defined by the American Society for Testing and Materials (ASTM International).

Components are the individual items of a Trench Drain System that may be purchased separately outside of a kit.

Concentrated Loads are load types applied to the full width of the Grating at mid-span and are not equally distributed across the full length of the span.

A Connector is used when two pieces of Pipe or Tube are connected together, either end to end or at an angle.

Copper is a naturally occurring metal that is very soft, malleable, ductile, and conductive. McNICHOLS offers many Copper products including Wire Mesh and Designer Metals.

Corrosion-resistant refers to a Metal's ability to withstand the deterioration that can be caused by chemical and natural elements.

Count is the number of openings per linear inch, measured from the center of any wire.

A CP Designator identifies a Carrier Plate by the intended Plank size it fits. An example is CP420, which refers to GRIP STRUT® 4-Diamond Plank x 2" Channel Depth.

Cross Bar Spacing is the distance from the center of one cross bar to the center of the next cross bar when referring to Grating products.

Cross Bar Type refers to a number of different types of cross bars that are used in the manufacturing of Bar Grating and Pultruded Fiberglass Grating. These vary depending on the size and spacing of the Grating as well as the method of manufacture. Some common types are round, rectangular and twisted square rod.

cross bars are one component that make up Bar Grating. cross bars run perpendicular to the bearing bars and can be either Welded, swage-locked, or press-locked into place.

Cross Wires are the wires in Wire Cloth that run parallel to the width (i.e., the short side of the roll or sheet). It is the same as weft wire and the opposite of line wire.

Cross-Rod Surface refers to Pultruded Fiberglass Grating that is available with a flush top cross-rod in some of the Grating series. In this case, the cross bars have a flat top surface that is normally finished to match the bearing bars, either with a smooth or grit surface.

Cross-Rods Color refers to Pultruded Fiberglass Grating that is available in several colors, though the typical colors are gray or yellow. Colors normally correspond to the specific type of resin system being used.

Cross-Rods Size refers to the size of the cross bar used in items of Pultruded Fiberglass Grating. The size and type of cross-rod may vary depending on the size, shape and spacing of the bearing bars.

A Cutout is an area of Grating removed to clear an obstruction or to permit pipes, ducts, columns, etc. to pass through the Grating.

Whether you require cut-to-length panels, sheets, planks, or rolls -- McNICHOLS can help. Our capabilities also include cut pieces and special shapes such as circles, cutouts and notches. Nationwide service centers are equipped with a variety of specialized cutting equipment. Your job will be cut-to-size to your specifications -- quickly and accurately!

Deburring refers to a mechanical process that removes sharp edges and burrs (thin ridges or sections of roughness) from metal.

Decking & Flooring refers to panel, plank or sheet products designed to be used as flooring over a solid surface.

Decorative refers to designer patterns carried by McNICHOLS in Perforated Metal, Expanded Metal, Wire Mesh, and Textured Metals.

Decorative Expanded refers to specifically designed Expanded Metal for use in architectural and decorative applications. These designs can be used to provide privacy and to control light and air while allowing visibility. Sun screens, room dividers and building facades are only a few of the design possibilities.

Decorative Mesh, or Designer Mesh, is a Wire Mesh product produced in a pattern designed for aesthetic value, specifically for appearance applications.

Deflection is the amount of “give” or sag the Grating undergoes under a given weight load. The standard acceptable deflection for most Bar Gratings is 1/4 inch.

Degreasing refers to a process where a material is immersed in a degreasing solution to remove all protective and lubricating oils.

Designer Textured Metals are Metal sheets with textured and/or colored finishes.

A Die is a tool that is used to punch specific shapes or sized holes into a piece of Metal.

A Dielectric is a material that acts as an insulator between two electrically charged bodies.

Discs are round, flat components used on the end of a handrail. They are available in several different diameter sizes and thicknesses.

In Double Crimp, before the wire is woven it is run through a crimping tool that crimps the wire (up and down). When the wires are then woven into Wire Cloth, the wire running the opposite direction lays in this shallow crimp helping hold the opening size and keeping the wires from slipping into an out of square position. This weave is used in general screening applications, is easy to weave, and is most common in small and intermediate size opening from 1/2" and smaller.

Drawing is mechanically forming Metal by tension through or in a die.

Drawing Quality materials are flat-rolled products produced from either deep drawing rimmed Steel or extra deep drawing Aluminum killed Steels. Special rolling and processing operations aid in producing an item that can withstand extreme pressing, drawing or forming, etc., without creating defects. The characteristics of Drawing Quality Steel are defined by the American Society for Testing Materials (ASTM International).

Ductility is the ability of a material to be stretched into a new shape without it breaking.

ECO-MESH® is framed, finished Wire Mesh panels used as a design element. Some applications are plant screens and rock walls.

ECO-ROCK® is a gabion-style Wire Mesh wall and containment system that can hold natural rock, recycled concrete, glass, and other materials.

Edge Banding is a strip of material welded to the open edges of Grating or other materials to increase structural integrity and occasionally to give a more finished look.

Electro-Galvanized, also called zinc electroplated, refers to the process of immersing steel in a zinc solution that has a current of electricity running through it. Materials can be Electro-Galvanized to increase durability, corrosion-resistance, and aesthetic shine.

Electro-Polishing is an electrochemical process used to polish Stainless Steel surfaces by removing microscopic amounts of zinc, sulfur, iron, and other materials from the metal surface. Electro-Polishing not only enhances the appearance of Stainless Steel, the process can also increase Stainless Steel's corrosion-resistant properties.

Designed as either fixed or adjustable pedestals, these products fit into the underside of Molded Grating and provide support for elevated flooring.

An Embed Angle is a Fiberglass structural shape designed to be embedded in concrete to provide a shelf for a Grating product to sit on.

End Pattern is the pattern of the perforations at the beginning and the end of the sheet. End patterns are either finished or unfinished. An unfinished end pattern is standard. A finished end pattern requires special tooling and is typically more expensive.

End Plates (also called Carrier Plates) are components that are attached to the end of a piece of Grating to make a Stair Tread. They are typically flat plates used with Bar Grating and some types of Plank Grating. They are sold in pairs and usually pre-punched with a slot and a hole.

End Plate Size refers to the length and width of the endplate used on Stair Treads. There are a series of standard size endplates that are pre-punched with a slot and hole for mounting purposes.

End Staggered is a pattern available in slotted Perforated Metal. It refers to when the bottom of each slot is aligned with the center of the bar on the row below.

Typically, Bar Grating Stair Treads come in a finished form with End Plates attached to the tread. Stair Treads can also be made without End Plates attached if they are going correctly welded in place.

EP Compatibility identifies the style, type, and size of the Grating for which the End Plates are used.

A structural shape produced with two legs typically set against each other at a 90 degree angle.

Equal Stubs refers to one method of cutting down a panel of Grating. With Equal Stub cuts, two equally sized pieces are cut with equal stubs so that, when placed side-by-side, the cross bars will be lined up and centered. The measurements for equal pieces are the same and the distance from the bearing bars ends (stubs) to the cross bars will also be the same on both ends of the cut piece.

Expanded Metal is a product constructed when sheet or coil materials are slit, then expanded to create diamond shaped patterns of specified dimensions.

Expanded Metal Construction Type is a characteristic that identifies the broad type of Expanded Metal. The types are Standard, Flattened or Decorative.

Expanded Metal Grating refers to a sheet or plate expanded into a structural open Grating ideal for catwalk and platform applications. Certain Expanded Metal Grating products can be flattened.

Expanded Metal Opening Size is the area in Expanded Metal enclosed by bonds and strands.

Expanded Style is a characteristic that identifies the accepted description of an Expanded Metal pattern. For Standard and Flattened products, the style describes the size of the design and the gauge of material. For Expanded Grating, it is the weight per square foot.

Fasteners are accessories used to secure Planks and Gratings to various supporting structures. Types of Fasteners include Anchors, Hold-Down Clips, Saddle Clips, Inserts, and J-Bolts.

Fiberglass Deck includes Molded and Pultruded Fiberglass flooring products designed to provide a walking surface with load bearing capability over short spans.

Fiberglass Grating Construction Type identifies the manufacturing method of Fiberglass Grating. The two types are Molded and Pultruded.

Fiberglass Handrail Systems are a series of products used as the components of a Fiberglass handrail system.

Fiberglass Plate Flooring is an ADA-compliant plate of Pultruded Fiberglass with a textured, slip-resistant surface. It is a tough, corrosion-resistant, lightweight, maintenance-free alternative to Steel plate.

The wires in Wire Cloth that run parallel to the width (i.e., the short side of the roll or sheet) opposite of line wire.

Finish is the coating, usually paint or galvanizing, which is applied to a Metal product.

Fire Retardancy refers to a material's ability to stop or reduce the spread of fire.

Fire Retardant Rating refers to a material's ability to withstand a fire-resistant test. For example, a material with an SPF Isophthalic polyester resin has a flame rating of Class 1 of 25 or less per ASTM E-84.

Fitting Type describes the type of fitting required and is used to identify Aluminum slip-on and Interna-Rail® components.

A Flange is a fitting that is used to attach a post to a floor or a railing directly to a wall.

A Flat Bar is an accessory added to cut-to-size Bar Grating that gives the product a finished look and prevents the panel or pieces from warping and twisting over time. May also be referred to as "Banding" and can be applied as either "Load" or "Trim" Banding.

Flattened Expanded Metal is manufactured by passing the standard Expanded sheet through a cold roll reducing mill parallel to the LWD. By flattening the sheet, the bonds and strands are turned down to produce a smooth and flat surface, reducing overall thickness and elongating the diamond pattern (LWD). Cross roll flattening is done by passing the Expanded Metal sheet through a cold roll reducing mill parallel to the SWD. The result is the same except the diamond pattern SWD is elongated. Material thickness may vary +/-10% from the published dimensions.

A FLEX ANGLE® is a structural shape made from slotted Pre-Galvanized Steel that is bent at an approximate 90 degree angle.

A Gabion is a wire container that can be filled with rocks, concrete, glass and other materials.

Galvanized refers to the process of applying a zinc coating to metal, often Steel or Iron, in order to increase corrosion-resistance.

Galvannealed refers to the process of galvanizing, then annealing a piece of metal, most often Steel.

Gauge is a standard measurement of thickness, generally used for metals under 3/16-inch. The higher the gauge number, the thinner the material. Thickness is the measurement from the top surface to the bottom surface of the metal sheet.

A Glass Mat is a group of Fiberglass pieces bonded together into one continuous cloth. It is applied around the rovings within Fiberglass Grating. The Glass Mat provides strength in the transverse direction and prevents chipping, cracking, and lineal fracturing.

Glass Rovings are filaments of Fiberglass that are grouped together to make up the densely-packed core of Pultruded Fiberglass Grating. They provide strength and stiffness in the longitudinal direction (called "span").

Grade denotes the composition of a metal for a given end use. For example, resistance to chemical corrosion heat.

Grating is an open grid assembly of metal bars, in which the bearing bars, running in one direction, are spaced by rigid cross bars attached to them. McNICHOLS Product Line of Grating includes six Product Types: Plank, Bar, Expanded, Fiberglass Molded, and Fiberglass Pultruded.

Grid Height identifies the height of the molded grid, also known as Grid Thickness. Molded Fiberglass Grating is available in square or rectangular grid configurations.

Grid Shape identifies the shape of the grid in Molded Fiberglass Grating. McNICHOLS offers this product in both square and rectangular grid patterns.

Grid Size identifies the size  of the molded grid pattern. Fiberglass Molded Grating is available in square and rectangular grid patterns.

Grit Application refers to the application of slip-resistant grit to the walking surface of Pultruded Fiberglass Grating. It can be accomplished in several different ways. The most common ones are "integral", in which the grit is embedded in the surface during the curing process, and "applied", in which the grit is applied to the top surface after curing, embedded in a resin coating.

Grit Color refers to Molded and Pultruded Fiberglass Grating which is available with a grit surface that is slip resistant. This characteristic identifies the color of the grit surface.

Grit Material identifies the type of material that makes up the grit applied on some Grating and flooring products. The application of this grit to the base material creates an abrasive surface that provides surer footing under slippery conditions.

Grit Texture identifies the consistency of a slip-resistant material known as grit that may be applied to a base material to create an abrasive surface that provides surer footing under slippery conditions. Grit Texture may be coarse, medium or fine.

Handrail Components are used in the construction of handrails for stairs and platforms.

Hardware refers to the miscellaneous nuts, bolts, washers, etc., that are used to attach accessories to other products or structures.

Heavy-Duty Frame Kits are optional heavy-duty hardnose frames for Trench Drain Systems. Each hardnose frame kit contains 10 frames at 24".

Heavy-Duty Welded refers to Bar Grating products that offer maximum load-bearing capabilities. The process to construct Heavy-Duty Bar Grating is the same as Welded Bar Grating with the difference being the size of the bearing bars and cross bars.

Hexagonal Hole refers to the hole shape of hexagonal Perforated Metal.

Hexagonal Mesh is a mesh with a hexagonal opening that is made by twisting the warp wires together at periodic intervals. It is not technically woven because there is no shute wire.

Hole Center is the distance from the center of one hole to the center of the nearest hole in the next adjoining row. Hole center is one of two measures of perforation spacing. The other is Open Area. Because Hole Center and Open Area measure essentially the same property (perforation spacing), you need specify only one or the other, not both.

Hole Pattern is the arrangement of holes on a sheet—either staggered or straight rows. In a staggered hole pattern, the direction of the stagger is normally parallel to the short dimension of the sheet. The standard pattern is 60° staggered. It is the strongest, most versatile and economical pattern of the Perforated choices. Also available are straight and 45° hole patterns, available by special order.

Hole Size refers to the diameter of the perforation. McNICHOLS carries a wide range of round hole sizes (from 0.020 to 1 inch) and can special order any hole size required as long as it meets minimum hole size requirements.

Hole Type determines the shape of the hole when referring to Perforated Metal. McNICHOLS carries round hole, square hole, slotted hole, hexagonal hole, and Designer Hole Types.

Hot Rolling is the mill process for shaping Steel in which the Steel is rolled under pressure at high temperatures between rollers. The squeezing involved in hot rolling refines the metal, making it tougher, stronger, more ductile and less porous. Hot rolled Steel is soft with a scaled (oxidized) surface and limited dimensional accuracy.

Hot-Dipped Galvanizing refers to the process of dipping metals, often Steel or Iron, into melted zinc in order to provide corrosion resistance. Hot-Dipped Galvanizing after manufacturing provides a more complete protective coating than Pre-Galvanizing.

HRPO, or Hot Rolled, Pickled and Oiled, is hot rolled Steel that has been dipped in an acid bath (pickling) to remove its scaly surface and then coated in oil to inhibit rust.

An I-Bar is an extruded Aluminum or Fiberglass bearing bar having a cross sectional shape resembling the letter "I".

An I-Beam is a structural shape produced with two flanges set at 90 degrees against a central vertical support.

Infill Panels are typically made from Perforated Metal, Expanded Metal, and Wire Mesh Sheets that are trimmed with U-Edging or other materials to finish the edge of the panel. They are non-load-bearing and often used as partitions, fencing, balcony and stair railings, facades, and more.

Inside Radius for handrail components refers to the radius of the inside of the "Elbow" or rail end as it follows the prescribed bend angle.

Installation Chairs refer to the components used to support the Trench Drain System as it is set up for installation.

Intercrimp refers to Wire Mesh that has been crimped in a zig zag fashion where there are multiple crimps between the intersecting wires when it is woven into Wire Cloth. This provides additional rigidity in holding the wires in place, and makes the mesh slightly stronger.

Interna-Rail refers to precision machined, maintenance-free Aluminum architectural handrail components. It is Aluminum Magnesium 6063-T6 with Anodized Coating and Stainless Steel fasteners.

The eight or ten digit number that identifies a product.

A Kick Plate is an accessory item that is attached to the edge of a piece of Grating and extends above the walking surface in order to provide a barrier that prevents shoes or boots from extending over the edge of the flooring.

A Kit is a variety of components packaged together that, when assembled, creates a pre-sloped trench drain of specified length.

Kit Channels Included refers to the channels included in a Trench Drain System Kit.

Ladder Rungs refer to products used as rungs or to cover existing rungs in a ladder.

Lancet Bar Size refers to the size of the bar between openings in Lancet.

Lancet Centers refers to the measurement between the centers of adjacent holes in Lancet.

Lancet Opening refers to the nominal opening size of the Lancet pattern.

Lancet Style refers to the style of the top of a ladder in a Fiberglass ladder or ladder/cage system.

Landings are made of several pieces of Bar Grating or Plank Grating secured side-by-side to a structural frame. Many applications call for a landing at the top of a flight of stairs.

LEEDS, or Leadership in Energy and Environmental Design, Compliance is a green building rating system. It specifically recognizes the recycled content of the material we supply.

Leg Size refers to the height of the legs on an Equal Leg Angle, typically used in reference to Structural Shapes.

Length is a characteristic that identifies one dimension of an item. It is commonly used to define the length, in inches, of a sheet, plank, panel or coil item. For load bearing Grating applications, the length is always recognized as the "span" dimension.

Leveling, also known as roller leveling, is a process that flattens wavy edges and buckles in metal sheets that may have resulted from the manufacturing process.

The Line Wire in Wire Mesh runs parallel to the length of the sheet (i.e., the long side of the roll or sheet). It is the same as Warp Wire and the opposite of Cross Wire.

Lip Size refers to the size of the front lip for Molded Stair Tread Covers.

Load refers to the amount of weight that the Grating will support. Load tables, found on, provide information on safe loading limits with respect to two types of loads: Concentrated loads, expressed in pounds, and Uniform load, expressed in pounds per square foot.

Load Banding is when the Banding (Flat Bar) strip of metal is welded to every bearing bar. Load Banding is commonly used in trench Grating applications where high loading requirements exist.

A Load Carrying Band is used in a cutout to transfer the load from unsupported bearing bars to the supported bearing bears.

Load Tables are tables showing the amount of load a material will bear safely on a given clear span, along with the amount of deflection (bending) that results.

Lockcrimp is a weave is used to provide and maintain accurate opening sizes. Unlike the rather rough lock of intercrimp, lockcrimp is formed by a straight section of wire with a "bump," another straight section of wire followed with a reverse "bump," etc. It is also used in some security applications because it is resistant to someone attempting to spread the wires.

In Expanded Metal, Long Way of Diamond, or LWD measures from the end of one diamond to the beginning of the next, in the same direction as the lengthwise orientation of the pattern.

In Expanded Metal and other products, Long Way of Opening, or LWO, is the inside dimension of the opening, measured across the center of the longest part. This is to be used when indicating the size to be cut from full stock size sheets or panels. The LWO is cut the length of the material.

Referring to Trench Drain, The Long Way of the Trench is the measure of the trench's length and is at a ninety-degree angle (nonparallel) to the direction of traffic.

Machine Run to Size refers to Expanded Metal as it comes off of the press with closed diamond edges.

Major Material refers to the primary material source found in a product.

Malleability is the ability of a metal to be shaped by pressing or hammering.

Margins are the blank (unperforated) area along the edges of the sheet. For stock sheets, the standard is minimum margins along the length and no margins along the width.

To specify other than standard margins, use the perforated round hole pattern quote form. Provide the width of each margin on all four sides (measured from the edge of the sheet to the edge of the first hole) and the direction to which the margin is parallel (side or length dimension). Manufacturing considerations may affect margins. If the margins requested are not possible, the quote you receive will specify the new margins. Below is an example of a margin specification based on the illustration to the right:

1 inch margins parallel to both 25 inch dimensions 0.75 inch margins parallel to both 48 inch dimensions.

McNICHOLS GRIP STRUT® is a product that features a non-slip diamond surface that is ideal for safety applications where mud, ice, snow, oil, and detergents can create hazardous walking conditions.

McNICHOLS GRATE LOCK® is an easy-to-install system of interlocking Grating planks, treads, and accessories that help provide safe, sturdy footing for floors, platforms, walkways, and other applications where non-slip performance is required.

The McNICHOLS® Hole Network is the system of 19 Metals Service Centers that McNICHOLS operates in cities across America.

McNICHOLS PERF-O GRIP® is made of large debossed perforated holes that provide slip-resistance and performance in every direction. The holes allow fluids, mud, chips, snow, and other accident-causing debris to fall through openings.

McNICHOLS TRACTION TREAD™ features panels that have a surface of perforated raised buttons. The perforations allow slippage to drain and break oil film, detergent, and other slippery agents away from the walking surface.

McNICHOLS® Hook Strips and Edges are Steel strips added to the edge of Wire Mesh or Perforated Metal. They can be used as shaker screens or be used to mount to equipment.

The McNICHOLS® Quality Policy is the mission of McNICHOLS CO. to provide superior products with superior customer service. It states, "Service, Quality and Performance", That's The Hole Story®.

McNICHOLS® Value-Added Services refers to the expanded service options McNICHOLS offers, including blueprint takeoffs, approval drawings, confidential shipping, fabrication services, and metal finishing options.

Mesh is the number of openings per lineal inch. The mesh is counted by starting from the center of one wire and counting the number of openings to a point one lineal inch away. For example, No.4 mesh indicates that in a lineal inch there are four openings.

Mesh Size refers to the number of openings per inch in a Wire Mesh product, measured from center to center of each wire. This characteristic identifies the number of openings in one dimension, typically parallel to the length, of a Wire Mesh item.

Mesh Type describes the shape and construction of Wire Mesh. It is either square or rectangular shaped, and either woven or welded.

Meshes Per Foot in Expanded Metal describes the number of diamonds per foot by the SWD and LWO.

Metal Plate refers to flat sheet or plate products designed to provide a flooring surface with no load bearing capability.

Method of Manufacture identifies how Handrail Brackets (a Product Type of Handrail Components) were made.

A Mill Finish is the finish generally produced by the mill. It is typically not shiny or scratch-free, which should be considered if aesthetics are critical to your application.

Minor Material identifies a specific grade of material within a larger material type. These include grades of Carbon Steel and Stainless Steel, alloys of Aluminum, and specific Fiberglass resins.

Molded refers to Grating products constructed by molding Fiberglass into a specified grid pattern of uniform thickness.

Molded Grating refers to treads for stairs made from molded Fiberglass Grating products.

MSCI, or Metals Service Center Institute, is a trade association for Steel service centers.

Approximately 700 species of tiny, malicious pests that tend to gather in a cloud over your head — also known as gnats, punkies, and midges. They prefer damp places, calm, humid days, and are more active at twilight and early evening. They are strongly attracted to artificial light. No-See-Ums require insect screen of at least 20 mesh or smaller.

Nosing refers to accessories attached to the leading edge of a Stair Tread to provide additional slip-resistance and support to the tread. McNICHOLS offers several types of Nosing -- checkered plate, corrugated, abrasive, or oxide grit nosing.

Nosing Color refers to the color of the nosing area of a molded Stair Tread cover.

Nosing Shelf refers to the two sizes of GRIP STRUT® Stair Treads available that have been designed with a nosing "Shelf" built into the plank. This shelf is a flat surface at the leading edge of the tread where a strip of cast abrasive nosing is usually mounted.

Nosing Type designates the type of nosing, such as Corrugated, Checkered Plate or Cast Abrasive.

Opening Size LWO identifies the opening size, in inches, running the long way of the opening in an Expanded Metal pattern. It is found under Expanded Metal (Flattened, Standard and Decorative) and for Expanded Grating. 

Opening Size SWO identifies the opening size, in inches, running the short way of the opening in an Expanded Metal pattern. It is found under Expanded Metal (Flattened, Standard and Decorative) and for Expanded Grating.

Outside Diameter refers to the outside diameter of a ball, hemisphere or U-Bend in the Product Line of Handrail Components.

Outside Dimension refers to the dimension from outer wall to outer wall of a tube or rod typically used to describe a structural shape.

A Pattern Name identifies a specific decorative or architectural pattern.

Pattern Number -- 88016 is a McNICHOLS identifying number that specifies a particular size and configuration of an Architectural product.

Percent Open Area is the total area of the holes divided by the total area of the sheet and is expressed as a percent. In other words, open area describes how much of a Hole Product is occupied by holes. Percent Open Area is important when determining the amount of light, air, or liquid that is able to pass through.

Perforated Metal is sheet or coil products with holes punched through them to create a specified pattern. McNICHOLS offers the largest selection of Perforated Metal in the nation, available in a variety of hole types including round hole, square hole, slotted hole, or hexagonal hole (See "Hole Type"). We also offer Perforated Metal in Designer patterns.

Pickled and Oiled refers to hot rolled Steel that is acid pickled to remove mill oxide. This is done to improve surface appearance, uniformity, and finishing qualities including paint adhesion.

Pipe/Tube Size identifies whether a handrail component is made to fit a pipe specification or a tube specification.

Plain Weave is an over and under weave without crimping or welding of the individual wire strands.

Plank Grating refers to Grating products with a variety of different walking surfaces produced by forming a sheet into a plank or through an extrusion process.

Plank Grating Construction Type is a characteristic that identifies the broad type of Plank Grating. The types are Plank, Walkway, Interlocking, Extruded Interlocking, and Heavy-Duty Plank. There are also various styles of Ladder Rung Plank Grating and Stair Tread Plank Grating.

Sheet metal 3/16-inch or heavier is referred to as a Plate. It is measured in fractional inches rather than gauge.

Polyamide Resin is a thermosetting liquid polymer that is hardened by exposure to heat.

A Polymer is a chain molecule composed of many identical groups, commonly found in plastics.

Post Sleeves are fittings meant to be set in cement to receive a railing post.

Powder Coating is a dry finishing method that involves spraying electrically charged particles of pigmented paint or resin onto metal. The electrical grounding of the coated metal causes the charged powder to adhere to the product surface. The item is then heated in a curing oven, allowing the powder to melt and fuse together to form a continuous, uniform coating that is highly resistant to corrosion, abrasion and cracking.

Pre-Galvanized refers to Steel that was galvanized, or coated in zinc, while still in its original sheet form. With McNICHOLS products, Pre-Galvanized Steel goes through the galvanization process before it is manufactured into Wire Mesh, Perforated Metal, Expanded Metal, Bar Grating, Plank Grating or other Hole Products. Pre-Galvanizing generally results in a smoother finish than Hot-Dipped Galvanizing.

Press-locked refers to weldless Bar Grating that is joined by pressing the cross bars into the tops of the bearing bars. The pressure forces some of the metal of the cross bars into a dovetail slot in the main bars, effectively locking the bars together.

Print Takeoffs are a Value-Added Service offered by McNICHOLS in which our CAD experts do takeoffs from our customer's drawings or spec blueprints to help determine what materials are needed to complete a planned project.

Product Form refers to the structure that any given McNICHOLS product comes in. Some common Product Forms are Coil, Sheet, Panel, Tread, and Plate.

Pultruded Grating refers to Grating products constructed with a series of Pultruded Fiberglass load bearing bars attached together in a specified pattern by Fiberglass cross bars.

Punched for Splicing refers to some Plank Gratings, typically walkway products, that may be ordered with pre-punched holes in the side channel to accommodate bolts on splice grates. These splice plates secure adjacent walkway plans end to end.

Punched Hole Type identifies the shape of the punched holes in the surface of some Extruded Plank Grating products. These shapes are diamond, rectangular, round or oval.

PVC Coated refers to a Primary Material type offered by McNICHOLS in certain Wire Mesh products. PVC Coated material is Galvanized Steel that has been hot dipped in plastic in order to make it more resistant to corrosion and other environmental influences.

Rail Ends, made for Handrails mounted to walls by their ends, are meant to attach the straight part of handrail back to the wall.

Random Shearing refers to the process of cutting sheets to size without regard to the position of the holes. This type of cut may leave jagged edges, prongs, and incomplete design patterns.

Random Stubs refers to the most cost-effective method of cutting down a panel of Grating. With Random Stub cuts, two equally sized pieces are randomly cut so that, when placed side-by-side, the cross bars may not line up. The overall measurements for equal pieces will be the same, but the distances from the bearing bar ends (stubs) to the cross bars will vary from piece to piece and end to end.

Rectangular Mesh refers to Welded or Woven Wire Mesh in a rectangular pattern defined by the number of openings per inch (mesh) in both dimensions.

Rectangular Opening refers to Welded or Woven Wire Mesh in a rectangular pattern defined by the opening size in both dimensions.

A Recticuline Bar is a sinuously bent connecting bar extending between two adjacent bearing bars, alternately contacting and being riveted to each.

Reference Number refers to a secondary identification number by which a handrail component can be specified.

Resin Content identifies the percentage of resin as a component of Fiberglass Grating.

Resin Name identifies the name of the resin used in Fiberglass products. Fiberglass products are manufactured using different resin formulations for service in a variety of applications and environments.

Reversible Grating is Grating constructed so that it may be installed either side up, with no difference in appearance or carrying capacity.

Ribbon Size identifies the size  of the ribbon in Expanded Ribbon Mesh.

A Ring is a decorative fitting shaped as a ring made from square or round solid bar stock.

Riveted refers to a type of Bar Grating composed of straight bearing bars and bent connecting bars which are joined at their contact points by riveting.

A Rod is a solid round or square structural shape.

Round Hole refers to Perforated material that is punched with round holes.

Rungs refers to Ladder Rungs and Ladder Rung Covers.

Saddle Clips, also known as M Clips, are used to secure Grating panels to supports.

Saddle Style identifies the style of the mounting to which the pipe or tube is attached on a handrail bracket.

Sand Blasting is a mechanical finishing. There are several types of Sand Blasting. With Sand Blasting, the surface is subjected to a stream of high velocity sand under air or steam pressure. The sand removes scale or encrusted material and creates a dark gray brushed appearance. Sand Blasting may be a good choice when there is a desire to improve the appearance of a standard mill finish. If you want a product sandblasted, specify this in the comments box during the request for quote process.

Sand Blasting is a process that is used to improve the appearance of a material. It removes scale or encrusted material by subjecting the surface to a stream of high-velocity sand.

Screen Plate is a type of Perforated Metal that is often specified as an alternative to Wire Mesh screens.

Sealing Kits refer to material that can be mixed and applied to the cut surfaces of Fiberglass products to reseal and protect them.

Selvage refers to the finished edges of the Wire Cloth running the length of the roll. The most common type of selvaged edge is produced in the weaving operation where the shute wire curls to go back across (and through) the warp wires. This looped edge is the selvage edge. It keeps the woven material from unraveling at the edges of the roll.

Series are groupings for McNICHOLS Grating types (bar or safety Gratings, for example) based on bearing bar and cross bar spacing as well as bearing bar size. Examples of series groupings are GAL, GCM-1, etc.

Serrated refers to a type of Bar Grating surface. Serrated surfaces have grooves and are often used for slip-resistant applications.

Shaker Screens, also known as Vibrating Screens or Hook Screens, are used in industry for sizing and separating products from heavy aggregate, to fine powders and grains, from foods like vegetables to scrap in recycling centers. Many times a year a Shaker or Vibrating Machine will have two to as many as 5 or 6 layers of shaker screen levels to size different size particles. The top layer would have the largest holes to screen out the large chunks. The screens below would have smaller openings than the one above it to screen out smaller particles.

Shearing refers to the process of cutting metal to size in order to produce various sizes and shapes.

Many items, including Perforated Metal, Expanded Metal, and heavy gauge Wire Mesh, are available as a sheet.

Sheet and Plate refers to a flat sheet or plate, but not a flooring product (see Molded/Pultruded Plate Flooring for that).

In Expanded Metal, Short Way of Diamond, or SWD, is measured from the center of the bond to the center of the bond across the short dimension of the diamond.

In Expanded Metal, Short Way of Opening, or SWO, is the measurement from the inside of the bond to the inside of the bond across the center of the short dimension of the opening.

The Short Way, or Span, of the Trench is the measurement of the trench's width. The direction of the traffic runs the same direction (parallel) as the span of the Grating. Since the bearing bars carry the load, they must be parallel to the Short Way of the Trench.

Shute Wires in Wire Cloth run parallel to the width (i.e., the short side of the roll or sheet). See line wire.

Side Staggered is a pattern available in slotted Perforated Metal. It refers to when slots are lined up in straight, single file columns but are staggered relative to those in the adjacent column. In other words, the center of the side of each slot is lined up to the center of the bar next to them.

A Sieve is a Wire Mesh product constructed by attaching a specific opening or mesh size to a round frame. These products are used in testing applications to size material.

SKU Type identifies the form in which McNICHOLS quality product is stocked. Typical SKU types are sheet, plank, panel, coil, piece and each.

Slip-on Fittings are lightweight cast Aluminum components that attach to pipe mechanically via a hex screw to make railing sections. These are available as either "in line" or offset design.

Slot Arrangement refers to the arrangement or configuration of the slots on a sheet -- either straight row, end staggered, or side staggered.

Slot Direction specifies whether the long dimension of the slot is parallel to either the width or length of the sheet.

Slot End Bar Width is the distance between the end of one slot opening to the end of the opening above or below.

Slot End Center is the distance between adjacent slots measured parallel to the slot's width.

Slot Length is the long way of the slotted holes that are punched in some Perforated Metal. The slot is described as having a width dimension in inches and a length dimension in inches.

Slot Shape (also called End Shape) is the shape of the slot ends, either round or square.

Slot Side Bar Width measures the distance between the long edge of a slot to the nearest adjacent long edge.

Slot Side Center is the distance between adjacent slots measured parallel to the slot's length.

Slot Width is the short way of the slotted holes that are punched in some Perforated Metal. The slot is described as having a width dimension in inches and a length dimension in inches.

Slotted Hole refers to Perforated material punched with slots.

Space Cloth is Wire Cloth designated by the aperture (open space) width, expressed in inches or fractions thereof. Space cloth specifications are typically used for mineral, ore, sand and gravel screening.

Span is the length of the Grating across two consecutive Bar Grating supports. Span includes both the supported and unsupported sections of the Grating. (See clear span)

Splice Plates are products used to connect two separate pieces of Plank Grating together to form a single piece.

Square Hole refers to Perforated material punched with square holes.

Square Mesh refers to Welded or Woven Wire Mesh in a square pattern defined by the number of openings per inch (mesh).

Square Opening refers to Welded or Woven Wire Mesh in a square pattern defined by the opening size.

In addition to achieving a certain length and width tolerance, shearing is used to make a sheet or piece square. Squareness is determined by measuring the distance between diagonally opposing corners. The amount a sheet is "out-of-square" is determined by taking half the difference of the measurements. Resquaring is then achieved by shearing the sides and/or ends.

In Perforated Metal, Staggered Pattern is a pattern in which the openings are not lined up "single file" but are offset alternately left and right, usually at a 60-degree angle. Contrasted with the less-common "straight" pattern.

Stainless Steel is a Steel alloy containing chromium and nickel and is known for its corrosion resistance. McNICHOLS offers many Stainless Steel products including Perforated and Expanded Metal, Wire Mesh, Bar Grating, Plank Grating and more.

Stair Treads are products used specifically as load bearing treads on stairs, either with or without integral end plates.

Stair Tread Covers are non-load bearing products used to cover existing load bearing Stair Treads to provide a renewed or different walking surface.

Stair Tread Type identifies the form of a Bar Grating Stair Tread. There are three types. Type A-Standard is an Aluminum Stair Tread finished with Corrugated Angle Nosing. Type B-Standard is a welded or press-locked Stair Tread finished with Checkered Plate Nosing. Type C-Special is available in either Steel or Aluminum and is finished with a Cast Abrasive Nosing.

Standard Expanded Metal refers to Expanded Metal products that are left in their primary expanded state (not flattened).The strands and bonds are set at a uniform angle to the plane of the sheet. It is also called regular, unflattened or raised Expanded Metal.

Straight Rows Parallel To is a term that describes the way a pattern of Perforated Metal holes fits on the sheet. Perforated Metal is often made by punching a series of straight rows, each offset or "Staggered" from the next. The way the pattern fits on the sheet is described by the direction of the straight rows as being parallel to either the "width" or "length".

Expanded Metal is composed of strands and bonds. Strands form the sides of the Expanded Metal openings.

Strand Thickness in standard Expanded Metal is the gauge or thickness of the sheet or coil from which the Expanded Metal was produced. In flattened Expanded Metal it is the overall thickness of the finished sheet.

Strand Width in standard Expanded Metal is the amount of metal fed into the expanding machine, which is slit and stretched with each stroke of the upper die. In flattened Expanded Metal, it is as the name implies, the width of the strand.

Striation refers to grooves or channels cut or extruded in the surface of Grating, usually parallel to the length, for the purpose of providing slip resistance.

Structural Quality is material applicable to the various classes of structures, indicated by the standard specifications, which is suitable for the different mechanical operations employed for the fabrication of such structures. Structural quality (the characteristics of which are defined by ASTM International) represents the quality of Steel produced under regular or normal manufacturing conditions.

Structural Shapes are products used to provide a supporting structure, such as I-Beams or unique shapes such as tube, rod or channel.

Stubs refer to the bearing bar lengths along the cut edge of a piece of Grating measured from the end to the nearest cross bar.

A Stud is an item that is welded to a piece of angle in order to create a fabricated product called embedment angle. Embedment angle is set into concrete to form the shelf for a trench on which Grating rests; the studs serve to lock the angle into the concrete.

Studs and Nuts are pultruded vinyl ester rods with optional partial length threading to accept thermoplastic hex nuts.

Surface Finish is the description, name, or numbering convention that describes the finish of a material's surface.

A Surfacing Veil is a reinforcing resin applied to Fiberglass Grating in order to provide unequaled strength and corrosion resistance.

Swage-locked refers to Bar Grating that is constructed through a swaging process in which cross bars are inserted in pre-punched holes in the bearing bars and then mechanically locked in place under a pressurized pinching process. The square cross bars in between the bearing bars are re-shaped, resulting in the cross bars being locked in place. swage-locked Bar Grating offers high strength and rigidity while being lightweight and virtually maintenance-free.

Tangent Length is the size of the straight portion of an Elbow from the point it completes its bend angle.

A T-Bar is one type of bearing bar shape in which, from the side, each bearing bar resembles a "T" shape.

Textured Finishes refer to metal sheets with rolled, 3-dimensional patterns.

The Hole Story® is the account of founder Bob McNichols which has come to symbolize the company's philosophy.

Thermosetting describes the method in which polymer cures resins. The resins, which are liquids, harden when exposed to heat.

A Toe Plate is a large Flat Bar often welded to the edge of Bar Grating for a platform or landing application as an added safety feature that keeps feet securely inside the perimeter of the landing.

Tolerance is the dimensional parameter specified by users of a material or established for the material itself. Tolerance indicates the amount of allowed deviation from the specified dimension.

Top Flange Space refers to the space between the top flange of adjacent bearing bars. Pultruded Fiberglass Grating is available in both "I-Bar" and "T-Bar" shapes, both of which incorporate a top and bottom flange.

Top Flange Width refers to the width of the top flange of the pultruded bar used for the Grating.

A Trade Name is a name or designation used to identify and distinguish a commercial product or service from others in the same field. Also called brand name. These will typically, although not always, be identified by a Trademark.

A Tread is a panel of Grating having carrier plates and nosing attached by welding, and designed specifically to serve as a Stair Tread.

A Trench Drain is a pre-cast drainage system or individual components designed specifically for a trench application.

The  number of the component that is known as a locking device for a Trench Drain System.

Trench Grating is Bar Grating cut with the bearing bars cut parallel to the span or width of the trench.

This identifies the number or type of the Trench Drain Kit. Each kit contains different quantities and types of components.

A Trim Band is when a flat metal bar is welded at the ends of every 4 to 6 bearing bars within Bar Grating panels, pieces, or trenches. It is a band which carries no load, but is used chiefly to improve appearance.

Trimmed Edges in Wire Mesh are when the stubs are removed, leaving only 1/16th to 1/8th wires along the edges.

Trimmed Overall Length is the overall length of a 1/2" Diameter Solid Round Bar U-Bend.

A Tube is a hollow round, square or rectangular structural shape.

Type CB refers to an M-shaped Saddle Clip that is placed over two bearing bars, then fastened through a central mounting hole to provide hold-down support for Welded, press-locked, and swage-locked Bar Grating products.

Type F (Clip) refers to an accessory used to connect two Molded Fiberglass Grating panels together side-by-side. They are made to fit the height of the Grating and come in three sizes, 1", 1-1/2", and 2".

Type G refers to a fastener (Clip) that uses a "G" shaped anchoring plate for attaching Pultruded Fiberglass Grating to structural supports.

Type F, also known as a C Clip, refers to an accessory used to connect two Grating panels together side-by-side. They are made to fit the height of the Grating and come in three sizes.

Type GFS refers to a fastener (Clip) with an asymmetrical "M" shaped Saddle Clip top that is placed over two bearing bars, then fastened through a central mounting hole to a cast malleable Iron fitting to provide hold-down support for Bar Grating products. This fastener will work with a range of bearing bar spacings and adjusts to bearing bar heights up to 1-3/4".

Type GG refers to a fastener (Clip) that uses two "G" shaped anchoring plates for attaching Bar Grating or Pultruded Fiberglass Grating to structural supports.

Type J refers to a hold-down Fastener (Clip) that secures panels to the support structure for most Rectangular Bar Grating products.

Type R, also known as an insert clip, refers to a fastener (Clip) that slides between two adjacent bearing bars to connect the bottom flange of the pultruded bearing bar to a support structure. They can be used as an alternative to the Type M or Type J Clip in many applications.

Type SSGC refers to a hold-down Fastener (Clip) that uses a "G" shaped anchoring plate to clip on the horizontal flanges of Structural Shapes. It provides hold-down support for press-locked and CLOSE MESH press-locked Bar Grating as they are attached to the supporting structure.

Type Z refers to a hold-down Fastener that secures panels to support frames for most Rectangular Bar Grating products. These are available in different sizes to fit different bearing bar heights.

A U-Bend is a decorative fitting made of 1/2" diameter solid round bar bent into the shape of a "U".

U-Edging refers to a U-shaped metal product designed to be cut to length and fit over a rough edge of a sheet to provide protection and appearance value. It is typically used with Perforated Metal, Expanded Metal, and Wire Mesh.

U-Edging Opening is the size of the opening between the parallel legs of U-Edging.

Uniform Cut refers to one method of cutting down a panel of Grating. With Uniform Stub cuts, two equally sized pieces are uniformly cut so that, when placed side-by-side, the cross bars will line up but may not be centered. The measurements for equal pieces are the same, but the distance from the bearing bar ends (stubs) to the cross bars will not be the same on both ends, but will be uniform from piece to piece.

A Uniform Load is a load type applied equally to the full width and span (length) of the Grating and is measured in pounds per square foot.

UV Protection guards against degradation over time from the sun's ultraviolet rays. It is available in the form of UV inhibitors or coatings.

VINYLMESH™ is a vinyl-coated Welded Wire Mesh product that comes in a variety of meshes, gauges, and widths. The product is easy to clean, weather-resistant, and corrosion-resistant.

Wall Thickness is the thickness of the material that makes up the wall of a pipe or tube.

The Warp Wire in Wire Cloth runs parallel to the length (i.e., the long side of the roll or sheet). It is the same as line wire and the opposite of weft wire.

Weave is the structural configuration of Woven Wire Mesh. Common weaves are:

  • Plain: Simple over-and-over weaving of strands without crimps (mechanical bends).
  • Lock Crimp: Warp wire bends tightly as it passes over and under the shute wire, helping to lock the weave and preventing chafing.
  • Intercrimp: Wires crimped in a zig zag fashion where there are multiple crimps between the intersecting wires when it is woven.

Weft Wires in Wire Cloth run parallel to the width (i.e., the short side of the roll or sheet). It is the same as cross wire and the opposite of warp wire.

Welded refers to a bonding method where pieces of metal are attached through a process of melting and cooling.

Grating in which the bearing bars and cross bars are joined at their intersections by welding.

Welded Square Opening Wire Mesh typically has larger openings than Woven Wire Mesh. In this product, wire strands are welded at each intersection, yielding an overall stronger construction.

Welded Wire Mesh is welded at all intersections and can be cut without the wires unraveling. Welded Wire Mesh typically has larger openings than Woven Wire Mesh and is more capable of maintaining its shape when stressed.

A Weld-on Elbow is a section of pipe or tube that changes directions according to a prescribed radius to form a shape like an elbow.

A Wide Flange Beam is an I-Beam with extra wide flanges as compared to a normal I-Beam.

Wire Cloth is another name for Wire Mesh. It consists of individual wires running perpendicular to each other that are either woven over and under each other, or welded to each other where they intersect to create a mesh screen.

Wire Diameter is the measure of thickness of the wires used in weaving or welding Wire Mesh. It is preferable to specify wire diameter in decimal inches rather than gauge.

In Wire Mesh, Wire Diameter Parallel Length is the diameter of the wire that is parallel to the length of the material. It is also known as the Warp Wire or Line Wire.

In Wire Mesh, Wire Diameter Parallel Width is the diameter of the wire that is parallel to the width of the material. It is also known as the Fill Wire, Cross Wire or Shute Wire.

Wire Mesh refers to sheet or coil products constructed by welding or weaving wire into a specified grid or pattern.

Wire Mesh Construction Type identifies how Wire Mesh is constructed and identifies the type of weave for woven products.

To determine the opening size for a Wire Mesh item, measure the distance from the inside edge of one wire to the inside edge of an adjacent wire in both vertical and horizontal directions.

Woven Square Opening Wire Mesh is the most popular mesh McNICHOLS offers. This product features a series of wires that are woven together, resulting in a weave pattern. The most common types are plain weave, lockcrimp weave, and intercrimp weave.

Woven Wire Mesh, also known as Wire Cloth, is made from wire strands that run parallel to the width of the roll (cross wires) and parallel to the length (line wires). The cross and line wires are interwoven, meaning they cross over and under each other.

Yield is a term that identifies the percentage of usable material obtained when cutting pieces out of a larger sheet of material. For example, if cut sizes from a larger sheet results in zero scrap (unusable) pieces, the Yield for that sheet would be 100%.

Zinc is a chemical element used in the hot-dipped galvanizing coating process for some McNICHOLS products. Steel products can be dipped in a molten Zinc bath which alloys with the Steel, protecting it from corrosion in many environmental circumstances. Materials that are Pre-Galvanized or Electro-Galvanized also contain Zinc properties.