Terminology of Perforated Metal

1. Hole Pattern

Hole pattern is the arrangement of holes on a sheet - either staggered or straight rows

2. Hole Size and Hole Center

Hole size is the diameter of the perforation. Hole Center is the distance from the center of one hole to the center of the nearest hole in the next adjoining row.

3. Open Area

Open area is the total area of the holes divided by the total area of the sheet and is expressed as a percent.

4. Thickness or Gauge

Thickness is the measurement from the top surface to bottom surface of the material. Gauge is the most common measurement.

5. End Patterns

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.

6. Length and Width

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.

7. Margins

Margins are the blank (unperforated) area along the edges of the sheet.