More snapped bolts

[Osprey6010]

Hi all, snapped the cat bolts off a while ago, it was the only way to get them off due to the rust.

Trying to work out how to get them out now, the car is on axle stands so limited space to move, but so far I have tried hitting them out with a hammer and chisel, and drilling them out. Drilling them will work, but will also take hours so was wondering if anyone had any other ideas, or if others have been in a similar issue.

Thanks for any help

 

[Rockhopper]

Grind them flush first then drill them.

 

[Osprey6010]

Thanks, that was my next guess, but I can quite get the angle grinder in there. Do you think a dremel with metal discs could do the same thing?

Grind them flush first then drill them.

 

[smorris_12]

With a sharp drill bit, drilling out a standard bolt ought to take minutes, not hours especially as years of heat and slow cooling means they should have lost any hardness and be dead soft.

<Egg sucking warning>

The usually way people fail is to spin a drill bit as fast as possible without pressing it into the work, resulting in a polished surface and a blunted drill bit. A decent, sharp drill bit with as much force as you can muster (and being careful at small sized) at slow to modest speeds will go through metal fast. Start with a 3 or 4mm bit for a pilot hole (the hardest bit) and work up.

If you're buying good bits, get some cobolt ones which will deal with hard metal too. Bit more fragile as a downside.

 

[TriggerFish]

Thanks, that was my next guess, but I can quite get the angle grinder in there. Do you think a dremel with metal discs could do the same thing?

Yes, a Dremel and a metal bit will do this I recently did mine this way - I also cut through back off the stud down too (the bit on the back of the flange) and then just hammered them out without drilling.

 

[Zummerset]

I drilled mine out with the slow and lots of pressure approach. Used 3 different bits, gradually increasing in size.

I think i may have resharpened the bits a couple of times in the process.
Definitely don't want it going too fast, you want it to bite in and cut.
Good luck!

 

[MikeyH]

Would it be helpful to use a little 3in 1 oil on the drill bit to keep it cool?

 

[Gregory_tolson]

Hit them with MAP gas until they are glowing red. Then spray penetrating fluid like PB Blaster and then remove with vice grips. Only drill if you got no more stud to grab onto

 

[pvr]

For some reason, my dremel metal disc always shatter (and fly at some enormous speed into anything and anyone ...). Has anyone found decent discs that don't shatter like that?

 

[Osprey6010]

Hit them with MAP gas until they are glowing red. Then spray penetrating fluid like PB Blaster and then remove with vice grips. Only drill if you got no more stud to grab onto

That's a good idea, might try that first before cutting anything away, thanks

 

[Osprey6010]

With a sharp drill bit, drilling out a standard bolt ought to take minutes, not hours especially as years of heat and slow cooling means they should have lost any hardness and be dead soft.

<Egg sucking warning>

The usually way people fail is to spin a drill bit as fast as possible without pressing it into the work, resulting in a polished surface and a blunted drill bit. A decent, sharp drill bit with as much force as you can muster (and being careful at small sized) at slow to modest speeds will go through metal fast. Start with a 3 or 4mm bit for a pilot hole (the hardest bit) and work up.

If you're buying good bits, get some cobolt ones which will deal with hard metal too. Bit more fragile as a downside.

Yep, slow speeds and plenty of power, I just can't seem to get the bits to bite? Cobalt bits are a shout, I might need to invest in them. Thankfully I'm only 10 mins away from a toolstation. Thanks

 

[Osprey6010]

For some reason, my dremel metal disc always shatter (and fly at some enormous speed into anything and anyone ...). Has anyone found decent discs that don't shatter like that?

Which ones are you using? I haven't had any issues with the branded dremel ones so far

 

[pvr]

Using the ones that came with the Dremel in the supplied box. Every single one has shattered that I used

 

[CuppaTea]

Yep, slow speeds and plenty of power, I just can't seem to get the bits to bite? Cobalt bits are a shout, I might need to invest in them. Thankfully I'm only 10 mins away from a toolstation. Thanks

Get left handed ones and they may pull out the bolt as you drill

 

[TriggerFish]

For some reason, my dremel metal disc always shatter (and fly at some enormous speed into anything and anyone ...). Has anyone found decent discs that don't shatter like that?

The thin brown/fibre snap all the time for me.

I have very good results with these - haven't snapped any, and wear most of them right down to the central metal ring (rather than them shattering the second they touch the thing I want to cut)

https://www.argos.co.uk/product/4581185?storeID=105&utm_custom6=LIA&utm_source=google&utm_medium=free_listing&utm_campaign=merchant_center&deeplink=true

 

[TriggerFish]

Get left handed ones and they may pull out the bolt as you drill

Unfortunately, not for this. There are straight groves cut into the stud, so it bites into the flange, and doesn't snip when the nuts are done up/undone. A left handed drill bit here would be money wasted (as much as they are usually worth having for threaded stud extraction).

Like this (stolen from Google images):

 

[CuppaTea]

What about one of these?