Drill out a knackered stainless bolt?

[DarrenSV650S]

Another of these POS halfords allen bits snapped when I was undoing my caliper mounting bolt. And in the process the stainless bolt head has rounded and now has a crack down the side of it. How? I have no idea







As you can see I've been attacking it with all my tools. Tried hammering bits in to it, grips, mole grips. Even got desperate and tried chiselling it round, which surprisingly didn't work.

Bit worried about damaging the nice new powdercoating but would drilling even work with it being a stainless bolt?

we use stainless sheet and stainless bolts at work which have to be drilled. you need to drill a small pilot hole with a GOOD quality drill bit, then use bit bigger drill bit.

[yorkie_chris]

Yeah same as anything else, work hardens a bit so try not to let drill rub.

[andrewsmith]

How tight is it in Darren?

You've done well to shear a allan socket cheap or not

I think a left handed drill bit might get it out. Failing that drill the head out, is the caliper threaded or is the threads just in the fork?

[DarrenSV650S]

Ok ta. What do you think, drill the bolt head off first and remove the caliper, or keep the caliper on there as a guide?

Originally Posted by yorkie_chris

Yeah same as anything else, work hardens a bit so try not to let drill rub.

its funny watching a couple of the muppets at work let the drill bit get red hot, blacken off then see them try and drill with it blunt as hell and work piece hardened.

Decent sharp bit, not drilling too fast should go through no probs.

[DarrenSV650S]

Originally Posted by andrewsmith

How tight is it in Darren?

You've done well to shear a allan socket cheap or not

I think a left handed drill bit might get it out. Failing that drill the head out, is the caliper threaded or is the threads just in the fork?

Tight as a futher mucker. But those allen sockets are pish. The caliper doesn't have threads, just a hole

can you get an Easy Out in there once you have a decent pilot hole?

[DarrenSV650S]

Originally Posted by leebex

can you get an Easy Out in there once you have a decent pilot hole?

Maybe if I took the wheel out, which I can't with the caliper on

Actually just realised if I drilled off the bolt head, I don't think there would be enough room to slide the caliper off.....

Bollox

[maviczap]

Originally Posted by leebex

can you get an Easy Out in there once you have a decent pilot hole?

If its snapped a socket piece, then I wouldn't go near it with an easy out, as if this snaps in there, it'll just compound the problem.

My guess is that some of the powder coat is acting like the strongest loctite you've ever used, I know I had exactly the same problem with a footrest hanger & a stainless steel
allen bolt.

I cut the head off the bolt and trashed the footrest hanger, as I couldn't get the remains of the bolt out.

So go carefully