Counter sink form CNC Punched in Aluminium sheet
Sheet metal fabrications often need to have countersunk holes ready to take countersunk screws when being screwed together. These countersinks have always been drilled in with standard pillar drills or counter bits. There is another production method that can be employed, which is to form the countersink shape in a CNC punch press or fly press. There are some good advantages to having formed countersinks in a sheet metal component:
1. The counter sink form will be even in cross section, no more triangular counter sinks!
2. The edge of the countersink will be softer than drilling the countersink in the sheet metal.
3. The formed countersink can be hit in the sheet metal at the same rate as a CNC punched hole which is clearly far quicker than drilling the countersink. This can lead to a big cost saving when there are many countersinks for each part.
CNC punched Sheet Aluminium panels
The only down side to CNC punching in the countersink form is that some harder materials like stainless steel are not suitable with standard CNC tooling but mild steel and aluminium alloys are perfect.