Round Holes are the most popular shape and give you the widest selection of diameters, gauges, materials and sheet size options. Holes are in staggered row (most popular) or straight row patterns. You may narrow your selection choices by using the left navigation pane or browse our stock list below
When you request a quote, if you do not specify a tolerance for quantity, McNICHOLS provides the ’exact’ quantity you requested. On large orders, you can lower cost by specifying ’standard’ tolerances. ’Standard’ tolerance is +/- 10% (plus or minus 10 percent). On an order of 50 sheets with a ’Standard’ tolerance, you would receive at least 45 sheets and no more than 55 sheets.
Standard Shearing (Cutting) Tolerances
Unless otherwise specified, McNICHOLS’ standard shearing tolerance is +/- 1/8 inch.
Standard Circle Shearing Tolerances
11 gauge carbon steel
24 gauge carbon steel
16 gauge stainless steel
24 gauge stainless steel
Maximum and Minimum
3 - 48 inch diameter: tolerance of +/- 1/8 inch, except 11 gauge which has a tolerance of +/- 3/16 inch.
Standard Flatness Tolerances
Flatness tolerances are measured as the maximum deviation for horizontal flat surface. The table below lists the standard flatness tolerances for both sheets and plates.
Tolerances for Sheets
16 gauge and heavier
Up to and including 60 inches.
Between 60 and 72 inches.
Over 72 inches.
17 gauge and lighter
Up to and including 36 inches.
Between 36 and 60 inches.
Over 60 inches.
Tolerances for Plates
To 36 Inches*
36 to 48 inches*
48 to 60 inches*
60 to 72 inches*
72 to 84 inches*
To 1/4 Inch*
1/4 to 3/8 Inch*
3/8 to 1/2 Inch*
1/4 to 3/4 Inch*
Standard Thickness Tolerances
The following table provides the standard thickness tolerance for perforated stock size sheet by material and thickness.
Plain (carbon) Steel
Standard Squareness Tolerances
Unless otherwise specified, McNICHOLS’ standard squareness tolerance is +/- 1/8 inch
Round perforated is a sheet or coil of material made from metal or plastic (see PlastiPerf) that contains holes punched by a die. The shape of the hole is determined by the shape of the die. For perforated with a round hole pattern, the die is circular. The die’s diameter can vary from approximately twice the thickness of the material being punched to over two inches. Common, in-stock sheet sizes for perforated round hole products include:
· 48 x 120 inches
· 48 x 144 inches
· 48 x 96 inches
· 36 x 120 inches
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 is 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.
As a rule of thumb, the hole diameter should be at least the same size as the thickness of the perforated material or larger. Preferably, the hole should be at least twice the size of the material thickness. As the hole diameter approaches the material thickness, the higher probability of tool failure. Modifications can be made in certain instances at additional costs. For stainless steel and similar higher-strength materials, it is preferable to specify a hole size at least three times the thickness of the material.
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.
Perforated sheets contain holes and material. 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 sheet is occupied by holes. If a perforated sheet has 60 percent open area, then 60 percent of the sheet is holes and 40 percent is material.
This open area table provides a quick way to determine open area for perforated sheets with a square hole pattern.
Note: Specify either Open Area or Centers, but not both.
Thickness is the measurement from the top surface to bottom surface of the material. Gauge is the most common measurement, but thickness can also be measured in fractional inches or millimeters. This gauges and weights chart can provide additional information.
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.
Length is the overall measurement of the long side of the sheet; width is the overall measurement of the short side of the sheet. Note that mill tolerances for length and width apply to stock sheets unless otherwise specified. If you have a stock sheet cut-to-size, cut tolerances apply. To specify other than standard tolerances, please use the perforated round hole pattern quote form to specify the required tolerances.
Quantity is the number of full sheets or cut pieces you need. Unless otherwise specified, the standard tolerance on quantity is ’Exact Quantity’. In other words, McNICHOLS will deliver the exact quantity you specify.
Bar width is the measure of the material between the outer edge of one hole to the outer edge of the nearest hole. If you specify bar width, be be sure that the bar width meets the guidelines for minimum bar width.
As a rule of thumb, the bar width should larger than the thickness or gauge of the material. Preferably, the bar will be at least twice the material’s thickness. For stainless steel and similar higher-strength materials, specify a bar width at least three times the material thickness.
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