There are three tool options to consider when drilling large-diameter holes in thick steel: twist drill bits, hole saws and annular cutters. 1. Twist drill bits. Especially in steel thicker than ...

We clamped the bit in a vice and used an angle grinder to touch ... All of these steel drill bit types would do well boring ...

Those that come closer need to be covered by metal plates; for big pipes, use a long protective plate. Electricians and plumbers spend lots of time drilling big holes, so they know a few tricks to ...