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

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0141.jpg

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0139.jpg

http://i88.photobucket.com/albums/k164/DarrenStewartTait/65bbaf59.jpg

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?

[leebex]

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?

[leebex]

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]

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

[leebex]

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

[DarrenSV650S]

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 :lol:

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]

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

[maviczap]

Take the spindle out, take off the brake line from the caliper, loosen the yoke and slide the forks upward to get the caliper off the disc.

Then take the complete lower fork somewhere or do it yourself and drill the caliper bolt out from the back.

[DarrenSV650S]

Take the spindle out, take off the brake line from the caliper, loosen the yoke and slide the forks upward to get the caliper off the disc.

Then take the complete lower fork somewhere or do it yourself and drill the caliper bolt out from the back.

I think there's only like an inch of clearance between the caliper and the rim


The holes looked pretty clean when I got them back from the powdercoaters but I spose it's possible

[maviczap]

Ok, then undo both brake lines and undo the yoke bolts and slide thw whole front end down. You'll need to raise the front to get the clearance. :)

[britaxcooper]

Well you've had enough logical replies so I don't think there's much else to advise, I have a TIG set at home so things like this I find are easily removed by welding a nut on

[maviczap]

Well you've had enough logical replies so I don't think there's much else to advise, I have a TIG set at home so things like this I find are easily removed by welding a nut on

Yes, but that would knacker the new powder coat on the caliper.

My suggestion was the non destructive method :p

[GIZZY66]

Thats a common problem with hex and torx bits , its the cold weather , the snap-on man was never done replacing ours , one day he came in and told us the remedy , put the tool you are going to use in your pocket for a few mins before use an it will be fine ! , 3 winters later and no replacements required , the answer to the stuck cap screw is hammer an under size socket onto the outside of the head , the socket grips the screw and the impact of the socket being hammered onto it brakes the corrosion or lock tight on the threads making it easier to unscrew .

[SIII]

If you are going to drill stainless, do it very, very slowly, use lots of coolant, gt85 or wd40 will do and as sharp a drill bit as you can get. Once you spin up the drill bit and get it hot, stainless will work harden very quickly.

I used to work for Presto, Osborne Mushet and Hydra tools in Sheffield (when Sheffield was the cutting tool capital) and the most common mistake I saw was the thought that you had to drill hard and fast ALL the time, and then complaining when drills broke!

[DarrenSV650S]

Ok thanks for the tips guys. I'll see what the access is like with it on the bike.

[britaxcooper]

Other thing that might be worth a try before drilling would be to cut a slot across the head and then try using some steel stip as a handle across it and seing it it will budge.

[DarrenSV650S]

Yeh that is worth a try. Although it is really tight.

But yeh I'll see if I can dremel a slot in it. The problem with these stainless bolts is the metal is very thin around the hex. It's an M8 allen hole and the standard bolt (which I was going to replace it with) is M6 so the metal is a lot thicker

[warmshed]

Thats a common problem with hex and torx bits , its the cold weather , the snap-on man was never done replacing ours , one day he came in and told us the remedy , put the tool you are going to use in your pocket for a few mins before use an it will be fine ! , 3 winters later and no replacements required , the answer to the stuck cap screw is hammer an under size socket onto the outside of the head , the socket grips the screw and the impact of the socket being hammered onto it brakes the corrosion or lock tight on the threads making it easier to unscrew .

Good advice, an impact driver is the tool I would use.
http://www.ebay.co.uk/itm/Impact-Driver-and-Bits-Set-Silverline-Tools-427633-/360139463111?pt=UK_Hand_Tools_Equipment&hash=item53d9fc19c7#ht_1425wt_698

[yorkie_chris]

I would drill head off, remove caliper, then get grips on remnants of bolts...

If you take mudguard off, you can remove spindle then spin fork lower to one side to get wheel out.

[GIZZY66]

thanks warmshed , sorry but i disagree with the impact driver , it requires to be struck firmly to be usefull and ive seen this causing fracture damage or issues when trying to insert the new capscrew , not gospel , just my thoughts .

[yorkie_chris]

Impact driver would not be my choice here.

[muzikill]

I had a bolt shear on the cases whilst rebuilding my engine. Cost me 20 quid to get it taken out at a garage but considered the cost of the damage my inexperience may have caused getting it out, it was worth it getting a pro to do it.

[Bagpuss]

welding would be what I would do here, weld into the hole then get some mole grips on it nice and tight and hopefully it'll come out. I had some right bugger screws that I couldn't get out some calipers, completely stripped but the trusty welder did the trick.

[britaxcooper]

Funny I replied to this topic earlier, My girlfriend told me last night her dad had broken a cap head holding the caliper mounting bracket to the fork leg on his CCM, granted it wasnt stainless but I did what I said in my post. TIG welded a "stalk" onto what was left and then welded a M8 bolt on and it came straight out, with no damage as the heat is so localised.

How are you getting on with the SV problem?

[warmshed]

thanks warmshed , sorry but i disagree with the impact driver , it requires to be struck firmly to be usefull and ive seen this causing fracture damage or issues when trying to insert the new capscrew , not gospel , just my thoughts .

Yes on reflection I agree with you and Yorkie, you would need to support the threaded part on the leg which would be difficult in this situation, sorry didn't think it through, glad you picked it up. Dave.

[GIZZY66]

Dave no slight was intended mate , just 30 years of mistakes to look back on :) , and hopefully 20 more years of mistakes to be made :smt023.

[DarrenSV650S]

First I dremel'd a slot in the bolt head and cut a strip of metal to fit in a normal socket but the metal just twisted in the socket when I tried to undo the bolt. So I tried the same with this weird socket. The metal strip didn't twist this time, but the bolt head just snapped.

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0147.jpg

So got the drill out and slowly drilled down through the head and in to the caliper a little. Dremel'd off the bits of the bolt head that were still attached, then got a 13mm drill bit and drilled off the head. Came off easier than I thought it would. Turns out I was wrong about the space between the caliper and the rim. There was just enough room to slide the caliper off the stud. It was a bit tight and took a lot of twisting side to side to get it off.

Only marked the inside of the caliper hole a little bit
http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0145.jpg

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0142.jpg

So then I got the mole grips clamped on to the stud, braced myself against the wheel, preparing to use all my strength to loosen it, and the feckin thing was loose! :eek:

Lots of confused faces later, and remembering what maviczap had said about the powdercoating, I looked at the bottom of the caliper hole.

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0143.jpg

http://i88.photobucket.com/albums/k164/DarrenStewartTait/DSCF0144.jpg

What's really worrying is that as far as I was concerned that bolt was torqued up to the right setting. And yet the stud was loose. Ok it might have worked a bit loose from me hanging off the breaker bar, but still pretty dodgy. I'm glad I decided to swap the bolts for standard ones now or I wouldn't have known. I'll be running a drill bit through all the caliper holes before they go back on.

Thanks for all the help guys :smt023

[maviczap]

Cool got it off without damaging the powdercoat Darren.

Amazing the strength of powder coat, I hadn't tightened the bolt that got stuck on my footrest hanger either, so I can understand why your caliper bolt was loose!

I Dremmeled out the powder coating on the swingarm linkage pivots, as I couldn't get the bearing's in after having it powder coated, so do the same with your calipers

[yorkie_chris]

Once you take the head off a bolt it should be loose, torque on bolt is putting tensile stress on it. Once you take this stress away there is no force on threads to result in friction.

But in this place I would use standard bolts.

[maviczap]

not the case with my footrest hanger bolt stuck in powdercoat

[yorkie_chris]

Aye corrosion or other mess inside threads creates friction

[DarrenSV650S]

Once you take the head off a bolt it should be loose, torque on bolt is putting tensile stress on it. Once you take this stress away there is no force on threads to result in friction.

But in this place I would use standard bolts.

Ahh yeh I see what you mean. I was thinking the stud would still be tight in the fork leg, but it isn't in there as far as it can go.

[Bagpuss]

Well done must have been a relief getting this off.