I was fitting a new RC40 silencer and connecting pipe, and while one of the bolts on the cat came off fairly easily, the other one sheared. I heated and whacked it, but all to no avail, so I resorted to drilling it out, which has been a nightmare. I've managed to make a 6mm hole through the centre, and I've removed a lot of the flange with a grinding tool on a dremel, but my drill bits are now pretty dull, and the grinding stone has all gone. I don't know what metal this thing is made of, but it's a tough old bastard. For the meantime i've put a 6mm bolt through, which will work temporarily, but I want to get the rest of the old bolt out soon, so that I can replace it with a proper 10mm one.
Does anyone have any magic ideas before i buy another grinding disc?