The following standards are intended to aid designers, engineers, and buyers of perforated product in selecting the correct item for their application. For simplicity, Ametco has adopted the general terminology used by the Industrial Perforators Association. For closer tolerances than described in this web site, please contact Ametco's sales department for details.
Sheet and Plate Size Specification
Standard stock size sheets and plates
(Typical: 36" x 96", 36" x 120", 48" x 96", 48" x 120")
The width and length will be standard mill shearing plus any stretch of the material by perforating, unless otherwise specified. For carbon steel sheets or plates, our tolerances are the same as the American Iron and Steel Institute.
Sheets and plates resheared after perforating
Length and width tolerances for:
thickness lighter than 1/8" = ±1/32"
thickness 1/8" to 3/16" incl. = ±1/16"
thickness heavier than 3/16" to 1/2" incl. = ±1/8"
thickness heavier than 1/2" = check with our Sales Dept.
If special re-square tolerances are required, consult our Sales Department.
Thickness of Metals
Steel Use "Manufacturer's Standard Gauge for Steel Sheets"
Stainless Steel Use the U.S. Standard Gauge Table
Monel Use the U.S. Standard Gauge Table
Copper, Brass or Muntz Use the B&S Gauge Table
Aluminum Use the B&S Gauge Table
Perforations (Open Area Calculator)
Round Perforations Staggered (60 degree pattern) is standard. Variations include the 45 degree staggered, and Straight Line Pattern.
Square Perforations Staggered Pattern or Straight Line Pattern.
Slotted Perforations Side Staggered, End Staggered, or Straight Lines. Slotted Perforations will be round end slots; specify if square end slots are required.
Custom Perforations Consult Ametco.
Spacing of Perforations (Open Area Calculator)
Spacing for large perforations will be designated by either Centers of Perforations, or by the Open area required. Spacing for small perforations will be designated by either Centers, or Open area, or if more practical, by the Number of Perforations to the Square Inch.
Pattern of Perforations (Perforated Patterns)
Unfinished End Pattern As a result of tool design, some specifications of staggered pattern perforations yield a pattern that appears incomplete at both ends of the sheet. This is an industry standard.
Finished End Pattern As a result of tool design, some specifications of staggered pattern perforations yield a completed pattern on both ends of the plate.
Staggered Perforations, both Round and Square The pattern stagger is normally in the short dimension of the sheet. Holes in a straight row pattern are normally parallel to long dimension of sheet.
Slotted Perforations Slots can be furnished parallel with either the length or width of the sheet in most cases.
Margins (Perforated Patterns)
Perforated stock size sheets and plates.
The long side of a sheet will be supplied with minimum margins. The short side of a sheet will have either minimum margins or no margins.
Sheets and plates resheared after perforating.
Special margins are available, but they must carry a tolerance within the limits of the perforating tool.
Unfinished end pattern is standard in the industry.
Flatness of Sheets and Plates
Perforated sheets or plates can, generally, be furnished to AISI flatness tolerances. However, if your job contains one of the following conditions you should consult Ametco's Sales Department.
Customer Supplied Materials
Material furnished by the customer must be referred to as "Perforating and Processing Only". All materials furnished must be of perforating quality. The weight of material furnished refers to the weight before perforating.
If work in addition to perforating is to be performed, please submit detailed information and sketches to Ametco.