Sheet metal is an incredibly versatile material used in metal fabrication. In this article, we are going to answer three frequently asked questions about sheet metal punching.
What Types of Metals can be Sheet Punched?
Sheet metal punching has come a long ways in recent decades. Today, sheet metal punching can be performed on almost all metals, like aluminum, brass, copper, iron, stainless steel and other special alloys. Because all these metals can punched, sheet metal punching is vital in the automotive, manufacturing, engineering, pharmaceutical and textiles industries.
How is Punch Metal Power Calculated?
You can calculate punch power using the following number sets and equation:
F = U x S x Rm
F = Punch force in Kilonewton (10 kN = 1 metric ton)
U = Circumference or perimeter of the punch shape (in mm)
S = Sheet thickness (in mm)
Rm = Tensile strength (in N/mm²)
For Stainless Steel (1.4301) 720 N/mm²
For Mild Steel (St 37) 420 N/mm²
For Aluminium (AlMg3) 220 N/mm²
f = factor between 0,5 – 0,95 when using punches with shear.
For round holes, the minimum diameter should be greater than or equal to the thickness of the sheet. For shaped holes, the shortest side should be greater than or equal to the thickness of the sheet.
How Long Does a Die Last?
A normal punching tool has a median tool life of between 400,000 and 600,000 strokes. However, you can extend the life of your mould by being diligent in the lubrication and cleaning of the mould with compressed air and clean rags. You should also periodically check the cutting edge of the punch and die, especially before sharpening. You can also extend the life of the die by punching on the right materials and using the right energy power.