Removing Rounded Allen Bolts

Originally Posted by L3nny

I've tried drilling already but I don't think I'm doing it right as it just made them even rounder.

You should be using a drill the next size up from the bolt shank diameter. once you have drilled deep enough the head should part company with the shaft.


With out the head and the foot rest assembly removed you should be able to get some Moleys on the remains.

If the original rearsets do survive, let me know as I might like to buy for race spares!

Good luck.

[maviczap]

Originally Posted by Sam Vimes

You should be using a drill the next size up from the bolt shank diameter. once you have drilled deep enough the head should part company with the shaft.


With out the head and the foot rest assembly removed you should be able to get some Moleys on the remains.

I did something similar with stainless disc bolts which rounded off, really hard to drill stainless steel too.

If it's not drilling out the the drill bit is probably blunt. Also, when drilling metal, it should be on a slow speed setting, as slow as possible really. If it spins to fast it will overheat the tip and blunt it within seconds. If you see smoke slow down!

Ryan

Originally Posted by jagryan85

If it's not drilling out the the drill bit is probably blunt. Also, when drilling metal, it should be on a slow speed setting, as slow as possible really. If it spins to fast it will overheat the tip and blunt it within seconds. If you see smoke slow down!

er.... LOL...




Also buy decent quality drill bits. I found out the hard way how a cheap drill bit can ruin something you are working on.

Allen bolts are really hard, normal drills tend to get hot and go blunt. Try and find some cobalt drills. start with a small drill and work up in sizes. You will need coolant/ lube. You should only need to go to the nominal thread size as the thread root is smaller so you should break through without going bigger than the original thread.
Dremel glass grinding bits are good for getting an initial small hole cut down into the allen screw.

Go to Toolstation.
Buy these

http://www.toolstation.com/shop/p53312?table=no

Buy this.

http://www.toolstation.com/shop/p750...ooling%20fluid

I swear by these, there is no material i have found they will not tear through.

C.

[SV650rules]

Before you go mad with the drill and get the head off you may get a stud remover bit into the head of bolt (they are a tapered hardened bit with a LH helix on them, the harder you tighten them the harder they grip the hole and because they are LH they turn in the 'unscrew' direction of a normal RH bolt or stud).

if that don't work you are going to have to drill them out, use the same diameter drill as the bolt or up to 1mm larger and when you reach the shank of the bolt the head should just fall off - Allen bolts are high tensile steel and pretty hard to drill, so you need a good quality drill bit (the ones you get from B&Q etc are normally only OK on wood (best Chinese hardened mild steel bits) get Dormer or De-Walt from screwfix or engineering supplier).

https://www.lowes.com/pl/Screw-extra...ols/4294607735

this is just an example, screwfix or similar may do them, Irwin are a pretty good quality.

I would avoid stud removers like the plague. They are very hard which marks them very brittle. Once you snap one of them off in the bolt you're in deep deep dwang.

[SV650rules]

Originally Posted by DuncanC

I would avoid stud removers like the plague. They are very hard which marks them very brittle. Once you snap one of them off in the bolt you're in deep deep dwang.

hard does not have to mean brittle - like everything else depends how much you spend, I have used them in industry for many years with great success, very often they are your last hope.

The other thing that helps is applying heat to the area, the expansion helps breaks the bond that is locking the bolt to whatever it is screwed into (heat also destroys loctite and other thread locking compounds) - maybe why welding something into a bolt head can work sometimes, the heat of the weld helps.