drilling a broken bolt

clockwise of course and it may grab the broken piece and turn it out for you. If it doesn't, at least you have a hole in which to use a stud extractor which you would have had to do anyway. Good luck Clint

Don't buy a drill for this if you don't forsee much of a need for one in the future. Go to a local rental place.

PAROADHOG wrote in article ...

If a bolt of a given diameter has corroded so badly as to break while attempting to unscrew it, a "stud extractor" or "easy out" of an even smaller diameter - and often harder and more brittle metal - is usually NOT the answer.

The end result is, often, finding oneself with the need to drill out something that is even harder than the original fastener - i.e. the broken portion of the not-so-easy-out which has spiraled itself into the fastener material - often expanding that same fastener even tighter into the hole.

An old machinist friend once told me that the ONLY time he used an "easy-out" was when he broke a fastener while installing it himself.

He would NEVER attempt to use an "easy-out" on a fastener that he hadn't just installed, since he could not be sure exactly what condition - and level of corrosion - the threads are in.

Careful, precision drilling is required. A skilled machinist can often drill the fastener out to the point where the fastener threads can be spiraled out of the hole, leaving the original female thread untouched.

OR welding a nut to the remaining piece of the bolt will often work. The heat from the welding often serves the purpose of breaking the corrosion.

People who are not skilled at this sort of thing, often end up with a hole that has progressed to the next standard size - at least.

It is often easier and quicker to simply drill the fastener out to the proper Heli-coil size for the original fastener size, and install a Heli-coil.

Not trying to discourage you, but removing broken fasteners is not usually an easy project - which is why, after more than 40 years' experience, I am quick to heat fasteners that seem to offer even the slightest resistance.

Bob Paulin - R.A.C.E. Race Car Chassis Analysis and Setup Services

Agreed. It always amazes me how people expect that if an 8mm solid steel bolt or stud has snapped right through without budging, that a 4mm easy-out is any sort of a sure fire way to unscrew the remains. It keeps me in beer money fitting helicoils after they've had a good old bodge at it and given up though.

Plenty of posts on here over the years to confirm that :)

I try them occasionally but only when the part is in the workshop and I can get it on the mill for proper repair if the easy-out fails. Every now and then an easy-out surprises me on a stud I thought would never budge but I use them with very delicate feel and if it's clear they aren't going to work I stop trying long before breaking them in the hole.

I would say that most easy-outs break because the top of the stud they are being used in hasn't broken off square. That puts a side force on the easy-out which snaps them off flush. First step if I ever use one is to mill the remains of the top of the stud square, mill or drill absolutely centrally, give it a damn good whack with a punch to shock it loose and then try the easy-out gently. Maybe 3 times out of 10 I get lucky and the other 7 means drilling out carefully until only the spiral of the thread is left and peeling it out with a scriber.

Also an excellent way to remove badly stuck oilway taper plugs in engine blocks. They tend to made of fairly soft steel and round the allen key location out before undoing. Drill right through, weld an old bolt into the hole and they pop out like they were never tight in the first place. Always annoys me that does :)

All excellent advice. Sadly most amateur mechanics won't heed it and then we get the posts on what sort of drill bit do I need to drill an easy-out out with

- lol.

I'd only add that a good swift belt with a hammer before trying too hard to undo a reluctant bolt often makes a huge amount of difference.

Most really experienced engineers don't break fittings in the first place. Anything that won't undo with the expected amount of torque gets a few hefty whacks or some heat plus a decent 6 point socket instead of the usual 12 point 'designed specifically to round off anything tight or rusty' one and the fitting comes out quite nicely.

Amateurs just tend to go at it until something breaks, either the tool or the fitting, and then have a good moan on here.

Dave Baker - Puma Race Engines

I'm not at all sure why women like men. We're argumentative, childish, unsociable and extremely unappealing naked. I'm quite grateful they do though.

Unfortunately the only right-angle drills available at the local rental places are the large construction models. I think I would need a smallish one. An air powered one would be nice, but neither air nor electric would be used often enough to justify the price I'd have to pay.

untouched.

corrosion.

experience, I am

resistance.

Thanks for the advice. I realize this is not an easy job, and with the limitations of my experience and tools, my plan at this point is to get one of the local mobile mechanics to drop by and do the job. The one I spoke to said he would try welding a nut to the end of the broken bolt, plus generally applying heat.

Tim B

You're right . I ass-u-me d the bolt broke while being tightened .

You can buy a small angle attachment for your regular drill for just a few bucks. They are not as hefty as a complete angle drill, but sufficient for one bolt like this.

Aside from the excellent advice from others about the EZ-out fiasco, I can only add one thing.

If you're going to ever do anything like this again, accept the fact that an angle drill is about the least accurate way to drill something like this and you MUST be 'dead on accurate' if you're drilling into your engine block for any reason. Considering the fact that if you make another mistake on this job it's going to likely cost you serious money, strip everything off and around the area with the broken fastener (including any removable body work if it makes the job easier) and use a brand new drill bit to drill out the bolt. Nobody liks to make 'extra work' for themselves, but if you can't see and reach everything you're working on you'll only make more frustrating work for yourself down the line. You need plenty of clearance for this kind of job if you're doing it at home, and working around a corner or in a blind hole will get you into nothing but trouble.

I once broke off a head bolt on an old Ford engine and drilled it out by hand so straight that all that was left in the block was what looked like a spring in the threads on the block. The threads in the bolt were the only thing left without my ever having touched the block itself with the bit, and I did it standing in my driveway with a hand drill. You can't do that with an angle drill in close quarters because you probably can't look straight down the bit as you're drilling (which is why I'm guessing you're thinking about an angle drill to begin with).

If the guy you're hiring pulls out an angle drill to go at your engine when it's in the vehicle, ask him if he carries insurance before he starts tearing up your motor.

Good luck, - Jeff G

If you have a piece that something can be welded to and you were putting it in when you broke it, that is one way to go. A dremil tool can cut a slot in it so a screw driver can work too.

Otherwise I have seen a bunch of folks use a cutting torch on them. The torch will cherry the steel bolt stub and blow it out as a liquid before it hurts the cast iron block.

I was really surprised when I saw it the first time...

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

nooobody wrote:

I've never understood why the "standard" socket in most sets is the

12pt. The number of times you need a 12pt over a 6 pt is relatively rare - and they are much worse for removing anything.

They allow finer movement on a T bar handle which can help when access is restrictive and for larger bolts they are fine - but for small bolts and rusty or badly seized ones you can't beat a 6 point or a surface drive socket which contacts on the flats rather than the corners of the hex.

Dave Baker - Puma Race Engines

I'm not at all sure why women like men. We're argumentative, childish, unsociable and extremely unappealing naked. I'm quite grateful they do though.

I realize that, but how often do you need a T-bar in a restricted location ? Not nearly as often as you remove an aged fastener that needs all the grip you can get. Besides, if you need a t-bar, that's when you *really* need a 6pt socket. The 12pt is the specialty socket, the 6pt should be the standard.

snapped

I decided not to drill it, and called a local "mobile mechanic" to see what he could do with it. He used a mig welder to first build up the bolt and then to attach a nut to it. Took him 4 tries before it held, but he got it out.

I also noticed some pretty deep pitting on the mating surface for the water pump, right where the o-ring would sit.I didn't want to use anything like silicone on it so I filled the pits with JB Weld and smoothed it out. I'll put the new water pump on tomorrow when the JB Weld has had a chance to harden thoroughly.

Tim B

12 Point sockets became the standard way back when 4 sided nuts were common. A 12 point socket would fit the 4 point nuts and also the then-new 6 pointers.

Sounds like a reasonable plan. I would also recommend chasing the threads in the block with a tap, and also using anti-seize on the bolts (don't want to do this again next time around, do you?)

good luck

nate

"This one goes up to 11 (12)." -Nigel Tufnel.

I think its a hold-over from box-end wrenches or non-ratcheting breaker bar type socket wrenches, where a 12-point wrench allows you a finer swing when wrenching in limited space. But with a ratcheting socket wrench, the "fineness" of the action is determined by the ratchet mechanism, not the socket. So yeah 6-points are much better (and I've got a full set of 6-point sockets for that reason).