Punching
Punching creates holes, slots, louvres and cut-outs in sheet and plate using CNC turret punch presses or dedicated punching tools. It is fast for parts with many standard holes and can form features like louvres, dimples and extrusions.
What it is
A CNC turret punch holds a set of punch-and-die tools and strikes the sheet at programmed positions, changing tools automatically. Shapes are built up by nibbling, and forming tools create louvres, countersinks and embosses.
For structural sections, hydraulic punching machines punch bolt holes in angles, flats and channels quickly.
Typical applications
- Enclosure and panel holes and cut-outs
- Perforated sheets and guards
- Louvres for ventilation
- Structural bolt holes in sections
- Electrical gland plates
Suitable materials
- Mild steel sheet
- Galvanised steel
- Stainless steel
- Aluminium
- Structural angles and flats
Points to consider
- Minimum hole diameter is roughly equal to the material thickness.
- Standard tool shapes and sizes avoid special tooling cost.
- Keep holes away from edges and bends (about 1.5–2× thickness).
- Laser cutting may be better for complex outlines without forming.
Frequently asked questions
Punching or laser cutting, which is better?
Punching is faster for many standard holes and can form louvres and countersinks. Laser is better for complex shapes and thicker material.
What is the smallest hole that can be punched?
Roughly equal to the material thickness; smaller holes risk breaking the punch.
Can louvres be punched?
Yes. Louvres, dimples and countersinks are formed with special forming tools on a CNC turret punch, alongside the punched holes.