helicoil and drillout costs?

[Richard Simpson Mark II]

So how does that work when they broke flush to the surface of the cylinder? How can you weld a steel nut to the stud in that situation?

[steve the grease]

So how does that work when they broke flush to the surface of the cylinder? How can you weld a steel nut to the stud in that situation?

You weld down the midle of the nut onto the end of the stud until the weld fills the hole up . The weld won't stick to the ally.
Lidl/Aldi/ Machine mart etc sell left hand drill stud extractors which are also good , you carefully drill down the midle of the bolt and the anti clockwise drill rotation tends to unscrew the busted stud.
' Easy outs' are terrible things which inevitablty spread the broken stud tightening it .... and then snap.

[zimtim]

I've never got an easy-out to work...screwing them in seems to force the stud to expand and wedge itself tighter into the female hole (sorry, that sounds a bit rude )

Had good results over the years with easy outs.
People tend use ones that are to big whatever size you think you need go down one size. Thing is to make sure you can get it in deep enough.

[Billy Bananahead]

A few pictures of stud extraction using welded nuts. Ooer.

[Billy Bananahead]

Back to front pictures.
Bottom picture is the offending broken stud, flush with the cylinder head, second is the welded nut as a "blob" very hot, camera couldn't really see it, and the third is the extracted stud. Engine is my 2013 Tiger 800XC.

[garyboy]

yep .. go for the expert !! ^^
welding, as shown and described on here, is much harder than it looks,
and I have tried drilling into a 6mm bolt set in ali .. almost impossible for the home bod,
the surface of the bolt will not be flat, .. almost impossible to drill centrally and squarely with a hand drill, not to mention the violent centre punch thing.
then a `small drill bit` .. it just wont happen will it (breaks, jumps, rips u finger off)

and then .. whumping a hardened steel anti wotsit thread destroyer exterminator bit into that poor innocent little bolt,
nah .. not going to work unless you are a mechanic or screwing expert

best get it done with an engineering chappie, (like the nice fellas on here)
dearer is cheaper in the end

[videoman]

I think every method has already been suggested and I would usually try a left handed cobalt drill first if the bolt has not corroded in the hole. Easi-outs are all well and good if you have a good quality set and are very careful with them. I've always found the smaller the diameter bolt to get out the more difficult it can be and out of the dozens I have removed I never particularly enjoyed this aspect of the job but I have always managed one way or another to remove a sheared bolt. I would say if you take it to a local engineering company an average price would be £25/£30 per bolt to remove.

I have been running a mobile thread repair business for the last seven years and try standing under an expensive Porsche 911 trying to drill out a sheared exhaust manifold bolt or a concours E type Jag will test your nerve and resolve.

Good luck

[bowber]

Easy outs for small bolts need to be thrown away, there is nothing easy or out about them!
Left hand drill bit and they quite often come loose before you're up to size, failing that you have to get close to size (hope you were accurate with your centre pop) and then start with a small chisel or screw driver to knock the top edge in all around while adding a slight unscrewing direction.
The heat from drilling helps and then the shrinkage from the middle being missing should also release the thread a little.
Using a drill guide bolted to the surface helps stop the drill wandering but again you need to have been accurate in it's setup.
Hope that makes sense as I've had a few glasses of vino tonight.

Steve