BIZOMAT MAKEOS · Fabrication
Perforated Sheet Open Area and Hole Count
What open area, hole count and weight does a perforated sheet with this hole and pitch have?
Open area percentage of perforated sheet with round holes on a 60° staggered or straight (square) pattern, holes per square metre, the solid fraction and the mass of a sheet of given size, thickness and density.
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How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Hole pattern | choice | Layout of the holes. |
| Hole diameter | mm | Hole diameter. |
| Hole centre distance (pitch) | mm | Distance between adjacent hole centres. |
| Sheet area | m² | Overall sheet area. |
| Sheet thickness | mm | Sheet thickness. |
| Material density | kg/m³ | Density of the sheet material. |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Hole pattern
- What it is
- How the round holes are arranged: in 60° staggered rows, where each hole has six neighbours at equal distance, or in straight rows on a square grid.
- Units and format
- Choose one of 2 options from the list: Round holes, 60° staggered; Round holes, straight rows.
- Example
- The form opens with “Round holes, 60° staggered” selected as a worked example. Choose the option that matches your case.
What this means: Hole diameter
- What it is
- The diameter of each round hole as punched in the sheet.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 1000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 5 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The open area rises with the square of the hole diameter.
What this means: Hole centre distance (pitch)
- What it is
- The distance between the centres of neighbouring holes; for a staggered pattern, between neighbours along the 60° lines.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 2000 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 8 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- The open area falls with the square of the pitch.
- Get it right
- It must be larger than the hole; the difference is the ligament width left between holes.
What this means: Sheet area
- What it is
- The overall area of the perforated sheet, length times width, used for the number of holes and the sheet mass.
- Units and format
- Enter a number in m²: square metres. The form accepts 0.000001 m² to 100000 m². Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 2 m² as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
What this means: Sheet thickness
- What it is
- The thickness of the sheet, used for the sheet mass and the ligament check.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0.000001 mm to 100 mm. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 1.5 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
What this means: Material density
- What it is
- The density of the sheet material, from the material data sheet; used only for the mass.
- Units and format
- Enter a number in kg/m³: kilograms per cubic metre. The form accepts 0.000001 kg/m³ to 25000 kg/m³. Required: the tool does not calculate until every input is valid.
- Example
- The form opens with 7850 kg/m³ as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
Method and formulas
- 60° staggered: open area = 90.69 (d ÷ p)² %, holes per unit area = 1.1547 ÷ p².
- Straight rows: open area = 78.54 (d ÷ p)² %, holes per unit area = 1 ÷ p².
- Mass = area × thickness × density × (1 − open fraction).
- Example: 5 mm holes at 8 mm staggered pitch give 35.426% open area.
Limitations
- Margins and unperforated borders are not included.
- Strength and stiffness of perforated sheet fall faster than the open area suggests; use the supplier’s effective properties.
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Specify perforated guards, screens and filters
- Estimate air or light flow through a perforated panel
- Work out perforated sheet weight
Who it is for
- Design engineers
- Fabrication supervisors
- Buyers
What you get
- Open area
- Holes per square metre
- Perforated sheet mass
Interpreting the result
- Open area sets flow and visibility; ligament width (pitch minus hole) sets punchability and strength.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 2607–2608. Topic reference; no source tables or recommended settings are reproduced.
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Open the Perforated Sheet Open Area and Hole Count calculator