Diamond Manufacturing Company
Perforated and Value Added Metal Specialists

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Flatness

Material distortion resulting from perforation can be minimized by roller leveling it to a desired flatness. Determined by measuring the distance between the highest point (or points) of the material to a perfectly flat table, flatness is dependent upon the material, its size, the percentage of the open area, and the existence and size of non-perforated areas and margins.

The following flatness tolerances are obtainable for any 120" of fully perforated sheets of either carbon steel, stainless steel or aluminum providing that the open area is 40 percent or less and the margins are less than half an inch. For parts where the longer dimension is less than 72", tolerances are held to 75 percent of what is shown and in instances where the material and open area are ideal, it can be made perfectly flat. For requirements that do not meet these conditions, obtainable flatness tolerances should be discussed with a customer service representative.

Whether it meets the above conditions or not, if you want the flattest material possible, specify Diamond Superior when requesting a quote or placing an order.

Thickness RangeCarbon Steel and Hot Dipped Galvanized SheetsStainless Steel and Heat Resistant Alloy SheetsAluminum Sheets
To 36" WidthDiamond StandardDiamond SuperiorDiamond StandardDiamond SuperiorDiamond StandardDiamond Superior
28-20GA5/16"1/4"7/16"3/8"1/4"7/32"
19-16GA7/16"3/8"1/2"7/16"3/8"11/32"
15-12GA1/2"1/2"5/8"1/2"15/32"7/16"
11GA - 1/4"1/2"1/2"5/8"5/8"9/16"1/2"
36" to 48" WidthDiamond StandardDiamond SuperiorDiamond StandardDiamond SuperiorDiamond StandardDiamond Superior
28-20GA7/16"13/32"1/2"15/32"11/32"5/16"
19-16GA1/2"15/32"5/8"19/32"15/32"7/16"
15-12GA5/8"9/16"23/32"11/16"9/16"1/2"
11GA - 1/4"23/32"5/8"13/16"3/4"11/16"9/16"
48" to 60" WidthDiamond StandardDiamond SuperiorDiamond StandardDiamond SuperiorDiamond StandardDiamond Superior
28-20GA1/2"15/32"5/8"19/32"15/32"7/16"
19-16GA5/8"19/32"13/16"3/4"9/16"17/32"
15-12GA13/16"3/4"15/16"7/8"3/4"23/32"
11GA - 1/4"27/32"13/16"31/32"15/16"3/4"23/32"

REMINDER: Unless Diamond Superior is specified, Diamond Standard tolerances are supplied.

Diamond Manufacturing Company

Diamond Manufacturing is a wholly owned subsidiary of Reliance Steel & Aluminum Co.

Reliance Steel & Aluminum Co.

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