Knockout Punch - Milwaukee, EXACT PG 13 / M 20, for Steel 3.0 mm and Stainless 2.5 mm, 4932430842

Milwaukee Knockout Punch PG 13 / M 20, Article 4932430842

Milwaukee 4932430842 is a knockout punch in size PG 13 / M 20 for cutting round holes in sheet metal. It works together with a knockout die. Maximum material is steel 3.0 mm and stainless steel 2.5 mm.

The punch is half the set

This is the first thing to be clear about when ordering. Knockout punching uses two parts: the punch, which cuts, and the die, which the material is drawn into. This article is the punch only. The matching die in the same size is 4932430914 - PG 13 / M 20, Ø20.4 mm.

PG 13 and M 20 are the same hole

The two designations describe one opening but come from different standards. PG 13.5 is the older electrical thread for cable glands; M 20 is the metric one. The hole is Ø20.4 mm because both threads pass through it - which is why the punch carries both markings.

Why steel and stainless differ

3.0 mm in steel against 2.5 mm in stainless is not caution. Stainless work-hardens - the material gets harder exactly where it is being cut. So the same punch handles a thinner stainless sheet, and exceeding the thickness chips the cutting edge rather than merely making the job harder.

Why punch rather than drill

A punch cuts the hole in one stroke and produces no swarf. The edge comes out clean and round, with no burn marks and no distortion of the sheet. In a panel or enclosure, where the hole is visible and takes a gland, that is the difference between finished work and work that needs filing.

What drives it

The punch threads onto a draw stud and is pulled through - by hand with a spanner or with a hydraulic tool. Milwaukee builds cordless hydraulic punch drivers in the FORCE LOGIC range where the cycle is automatic. The drive does not change the hole size; only the punch-and-die pair sets that.

Maintenance

Lubricate the cutting edge before every punch. Dry punching is the main reason a punch goes blunt early - friction and heat land on the edge instead of being carried away.

Technical specifications

Questions and Answers