Broken drill bit

[Kram]

Could try a diamond core drill, chose one with a centre bore just bigger than your broken bit and it will guide it, but it will be slow...
www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Drills/Diamond-Core-Drills
www.ebay.co.uk/itm/282497766997

 

[jordan1]

Could try a diamond core drill, chose one with a centre bore just bigger than your broken bit and it will guide it, but it will be slow...
www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Drills/Diamond-Core-Drills
www.ebay.co.uk/itm/282497766997

Those are more for ceramic tiles, glass etc, rather than metals

 

[hal 1]

I can get circlip pliers down the hole and have tried already but I think I'll need to loosen the bit first, I've had an idea to make some sort of clamp to weld a nut to and force it from behind like eddy suggested.
I'll keep you all updated and show some pics, only if it works mind you

Thanks

 

[hal 1]

Well, would you believe it !!
I've gone and got the bit out.
If you remember I said I could see the tip of the bit through the pilot hole, well I was checking out what to do I thought " I can get a nail to that "
So, long nail with the tip ground to more of a point, then with a nail punch on the end carefully balanced I got a few good knocks to it and it moved, a couple more goes and it came out easy

It's not all over yet, I still have to finish off the drilling of the stud, I'll do that half mil by half mil
Then clean the thread.
So thanks for the help and suggestions
Much appreciated
Hal

 

[knighty]

glad you got the bit it, but you should step up the drills more than half a mill at a time

if you only add .5mm each time you're hardly taking off any metal (0.25mm each side)

too easy to slip/polish the bolt instead of cutting into it


also it's much better to have the drill spinning slow and push hard instead of going faster and pushing gently - same thing again, it's so you cut the steel instead of slipping over it / polishing it
(also generates less heat)


also... left handed drill bits work really well... I've had good results with bolts spinning out with a left handed drill bit (nor normally right away, but after a couple of size step ups)

I didn't really expect much from them so just bought a cheap set of 5 left handers on ebay,... but they're still going strong (hardly ever used)

does mean you'll need to use a battery drill t spin them in reverse :-)

 

[Pete.]

I agree with Knighty. Stepping up in small increments is a recipe for a grab-and-snap. Now you have a pilot hole choose a bit that will drill out as much stud as possible without taking out the threads. A left-hand drill bit would be even better as it will probably get half way through then un-screw the stud.

 

[hal 1]

Ok chaps I'll use larger bits, left handed bits ? Sounds interesting, I'm in no rush with this job so I might just get myself some of those

Thanks

 

[EddyP]

I've had a lot of success with a LH drill bit too, managed to get a broken head bolt out with one, it caught and just unwound, was really impressed:

http://www.ebay.co.uk/itm/Sealey-5p...471617&hash=item4894cf0e83:g:qQwAAOSwFlxZZx~8

 

[hal 1]

SORTED !!!
Treated myself to a set of cobalt drill bits, vat free at M M today, Also got something else, make the most eh ?
So drilled it out in stages using plenty of cutting oil, got it to just right and then cleaned up the thread with a tap, well pleased with the job