Stuck caliper bolt

[svrash]

On my GSXR calipers, I'm changing the pinch bolts to stainless steel

I've changed all but 2 bolts which I've tried to get out with a impact driver but it won't go, i can't get the trusty mole grips in to grip the bolt

I can get in to the bolt from the back so my plan is to drill the centre of the bolt and hope the drilling will turn the thread and undo the bolt or if that doesn't work then tap a M6 thread in the bolt and try and undo it by doing the M6 bolt up

My problem is i don't know which size hole to drill to get a M6 tap for and i can't find any thing on the nerd :?

[svrash]

Found it http://www.engineershandbook.com/Tables/tapdrill.htm

[Skullmonk3y]

1 be lol

[svrash]

For an M6 thread with a std pitch of 1mm youll need a 5mm drill. Good luck with it, I know what lil barstewards they can be lol
Well if it don't work, I'll drill the whole thing out and re-tap it completely :wink: now i know the size hole to drill :lol:

[raymond smith]

5.1mm is the right size but you have to make sure it,s bang in the centre. if you fail you can have a thread repair insert fitted

[21QUEST]

Hope all goes according to plan. Good luck.

Cheers
Ben

[Sid Squid]

Using a drift squarely on the head of the bolt, and with the rear of the caliper adequately supported, preferably on an anvil of some kind - this can be the head of a large hammer on a firm surface, give it a moderately heavy, sharp whack - no need to Gorilla it - it'll come out, they always do.

Much preferable to drilling things.

[Razor]

Have you used some releasing fluid and given it a long soak?
Plus gas always works for me.