A perforated panel is punched hole by hole from the tooling in the turret, to the pattern on your drawing. Because the program places every hit, the pattern sits exactly where the design puts it: solid borders at the bends, fixings and welds, dense field where the airflow is needed, and nothing running off the edge of the part.
Open area, the number you specify
Open area is the proportion of the panel that is hole rather than metal, and it sets airflow, light and visibility through the panel.
For round holes in a staggered 60 degree pattern, the most common arrangement:
Open area (%) = 90.7 × (d ÷ p)²
where d is the hole diameter and p is the centre to centre pitch. For a straight line pattern, use 78.5 instead of 90.7.
So 5 mm holes on 8 mm staggered centres give roughly 35% open area, and the same holes on 10 mm centres give about 23%.
Where perforated panels earn their place
- Ventilation panels and doors for cabinets, kiosks and plant rooms
- Machine guards, covers and safety screens
- Engine, generator and compressor housings
- Speaker, sensor and lighting covers
- Architectural screens, balustrade infill, sunshades and cladding
- Shelving, trays, baskets and food service equipment
- Acoustic panels and filter screens
What you get
Faster turnaround. The perforation, the mounting holes, the cut-outs, the formed features and the outer profile all happen in the same setup, so the panel comes off the machine finished rather than moving between machines.
A consistent result. Same program, same tooling, same datum, so the hundredth panel matches the first.
Lower cost per part. Programming and setup are spread across the run, and there is no second operation to pay for.
What drives the price
Hole count. The punch makes one hole per hit, so machine time tracks the number of holes. The same open area achieved with fewer, larger holes runs faster and costs less.
Tooling. Standard hole sizes run straight from the turret. If a pattern calls for a size we do not hold, tell us early and we’ll suggest the nearest standard size.
Material and thickness. Thicker material and stainless take more tonnage per hit than mild steel.
Quantity. Larger runs spread the setup across more parts.
FAQs
How do you calculate open area?
For round holes in a 60 degree staggered pattern, open area is approximately 90.7 × (hole diameter ÷ pitch)². For a straight line pattern, use 78.5 instead. So 5 mm holes on 8 mm staggered centres give roughly 35%.
Can you perforate a part that also needs folding?
Yes, and it is one of the main reasons to punch rather than buy stock sheet. The program places the pattern clear of the bend lines, so the fold happens in solid material.
What materials can you perforate?
Mild steel, stainless steel, aluminium, zinc-coated and ZINCALUME® steel, brass and copper.
Send us your drawing
We’ll come back with a price and a lead time. See our punching and forming capability, the full sheet metal punching guide, or custom perforation vs stock perforated sheet if you are deciding which way to buy. Get a quote.
