Phenolic Resin - Phenolics are in the same family of polyester, vinyl ester and epoxy resins. Phenolics are composed of phenol and formaldehyde. They are the best organic material when it comes to safety in the event of fire. They are as strong as Iso-Polyester or Vinyl Ester Resin Grating but with lower smoke and flame levels

Pickled and Oiled - Hot rolled steel that is acid pickled to remove mill oxide, improving surface appearance, uniformity and finishing qualities including paint adhesion.

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

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

Random Shearing - Cutting sheets to size without regard to the position of the holes. Typically results in open holes at the margins (see bond shearing).

Selvage (wire cloth) - The edge or border of wire cloth, finished to prevent unravelling (versus a raw or cut edge). Types of selvage edges include looped, folded, welded and fine mesh border pattern. Selvaged edges are not available on special order or cut-to-size pieces.

Series (grating) - Most McNICHOLS grating types (bar or safety gratings, for example) are grouped into series (GAL, GCM-1, etc) based on bearing bar and cross bar spacing and bearing bar size. The series designations are provided on the grating’s product page, which can be reached using the ?Products? tab at the top of every page.
The series designation is required in order to identify the correct load table for a specific grating.

Shearing - Cutting expanded metal to size to produce various sizes and shapes.

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

Span (bar grating) - 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)

Space Cloth (Wire Cloth) - 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.

Squareness - Products are square within manufacturing tolerances. Should squareness be critical, sheets can be square sheared.

Standard Expanded Metal - Also called regular, unflattened, or raised expanded metal. Expanded metal as it comes from the press. The strands and bonds are set at a uniform angle to the plane of the sheet.

Strand (expanded metal) - The single metal strip that forms the border of the diamond, or opening in the expanded metal.

Strand Thickness - In standard expanded metal, it is the gauge of the sheet's thickness. In flattened expanded metal, it is the overall thickness of the finished sheet which includes the heighth of the raised strands.

Strand Width - Amount of material fed into the press to produce one strand.

Striation - 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 - 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 the American Society for Testing Materials) represents the quality of steel produced under regular or normal manufacturing conditions.

Stubs (bar grating) - The bearing bar lengths along the cut edge of a piece of bar grating measured from the end to the nearest cross bar.

SWD - (Short Way of Diamond) Distance from an outside point on a bond to a corresponding outside point on the following bond across the short distance of the diamond opening. Sometimes called pitch. Also the distance across all of the short openings of all of the diamonds in the sheet.

SWO - (Short Way of Opening) Distance across the short opening of the diamond from a point on the inside of the bond to a corresponding inside point of the next bond.

Thermosetting - Describes the method by which polymer resins are cured. The resins, which are liquids, harden when exposed to heat.

Trim Band - Bar grating panels, pieces, or trenches can be banded or have a flat metal bar welded to the ends of the bearing bars. A Trim Band is one where the flat metal bar is welded at every 4 to 6 bearing bars. Trim banding is commonly used for pedestrian traffic applications where loading is not a factor.

Warp Wire (wire cloth) - The wires in wire cloth that run parallel to the length (i.e., the long side of the roll or sheet) (same as line wire) - opposite is weft wire

Weft Wire (wire cloth) - The wires in wire cloth that run parallel to the width (i.e., the short side of the roll or sheet) Opposite of warp wire.