Perforation types for perforated metal sheet

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.

Spacing of Perforations

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 

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.

Flatness of Sheets and Plates

Perforated sheets or plates can, generally, be finished to AISI flatness tolerances. However, if your job contains one of the following conditions you should consult Ametco’s Sales Department.

• Perforated sheet has extra wide margins.
• Blank areas required within the perforated area.
• Perforated sheet has a large percentage of open area.
• Heavy gauge metal in relation to the size of the perforation.
• Special alloys.
• Stretcher leveled sheets.