Square Holes

Slotted Holes

Slotted Perforations ­ Slots can be furnished parallel with either the length or width of the sheet in most cases.

Custom Perforations

End 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.

Margins

Minimum Margins

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 re-sheared 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

Types of Perforations

Spacing of Perforations
Spacing for large perforations will be designated by either c
enters  of perforations, or by the open area required. Spacing for small perforations will be designated by either c enters, or open area, or if more practical, by the n umber of perforations to the square inch.

Pattern of Perforations
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.