broken cylinder head stud

[Colin Wilks]

I remember using an extractor bit many years ago to good effect. Leaving plenty of meat in the stud to be removed means they reduce the risk of damaging the female thread. Worth a try in the first instance I'd have thought.
See https://www.cromwell.co.uk/shop/lubrican...TL0751013D

[Charles P]

I remember using an extractor bit many years ago to good effect. Leaving plenty of meat in the stud to be removed means they reduce the risk of damaging the female thread. Worth a try in the first instance I'd have thought.
See https://www.cromwell.co.uk/shop/lubrican...TL0751013D

I've never known one of those extractors work on an old stud that's broken through seizure

[ollie cox]

hi all

going to dry drilling pilot hole today, thank you for the pdf, will come in usefull, yes the stud was a old rusted one, but i probably should i realised i was exerting a little to much force. will keep you updated, but thankyou for your help what ever the outcome

[Austin in the Shed]

If put the head on as a guide spot the end of the stud with the largest drill that will go down the hole.This will give you a centre.then drill down through with say a 5 mm drill ,if you have a helper get them to "eye up" that you a still drilling square.
Check that the drilling you have made looks central,if so ,with or without the head on drill out to 6.8mm.
If the hole is true you should have reduced the stud to a spiral down the hole.
With a plug tap try to pick up the existing thread,this is where it gets tricky,sometimes I've used a tiny chisel to pick up the start.You have to be really careful,bit at a time.
If all else fails providing you don't break the tap in it,you can helicoil it back to size

[AustinWood]

When removing rusted head studs I try to shock them to free them up. I do this by dropping the head onto the engine and then hammering the stud as if it were a nail. I put the head in place to help avoid bending the stud.
Shocking studs this way often loosens them.

[Adrian Payne]

Hello Ollie
Whereabouts are you. Do you know of anyone with a TIG welder.
Welding a nut to the broken stud, or if it has sheared off flush, build up the stud with weld and then add a nut.
This method has never failed to get the stud out. Welding causes the stud to shrink and loosen itself.
Adrian.

[James Anderson]

For cutting into hard metals, I've always found cobalt drill bits to be the best.

https://www.cromwell.co.uk/shop/cutting-...EN0268490K

Thanks Jeff.

[Chris KC]

I guess the old one snapped taking it out.

whilst putting new cylinder head studs in.....one stud snapped flush with the block

I take your point Austin but not quite what the OP said....perhaps I'm being pedantic again!

[Burky]

There is a tool called a stud extractor you could use, bit like a tapered left handed tap, drill a hole in the centre of the broken stud, put point of the extractor in the hole and turn anti-clockwise. The extractor will bite into the stud and wind it out. I did lots of these when I as an engineer. Cheers. Burky

[Bob Culver]

Someone on the old website commented that the so called Easy Out was the most inappropriately named tool ever and I fully agree. Primarily intended for bolts or studs broken by tension not torsion and not tight in the bore. A broken hard steel  Easy Out hugely compounds problems and best avoided.