Both a step drill bit and a knockout punch seem to be very similar, in that they both make holes in a metal box. The step drill seems to have an advantage, since it can make several size holes using ...
I have some aluminum / aluminium strips that are about 3 mm thick and about 20 mm wide. I need to drill some holes in them. The holes will be 3.5 mm. What type of drill bit do I need? What speed ...