Peek the Geek

I was using a hex wrench with a ball end like this



to try to remove a steerer clamp bolt on a Thomson Elite stem.

The ball part of the wrench snapped off and is now stuck in the head of the bolt, and I can't get it out.

I can't grab it with a needlenose, because the broken piece is flush with the top of the bolt. There's nothing to grab. I tried drilling into the piece of wrench in the hopes of pulling it out once a bit was in it, but the bit won't drill into the tough steel.

Any advice?

veganboyjosh

someone in another thread regarding another issue suggested that aluminum expands more than steel when heated, and pouring boiling water over the part was the remedy in that case.

what's the bolt made of?

Ray Dockrey

Is there enough room to take a dremel tool and cut a slot across the bolt? Then you could take a screwdriver and back it out.

dwood

Try using a small drift punch [perhaps 3/32"] and tap the broken piece of allen wrench on its edge from different angles. This should 'un-wedge' it and it will fall out. Be careful not to hit the hex area of the bolt itself. If you swage the hex hole you might permanently lock the broken piece in requiring more extreme methods of removal.

Just for future reference . . . the 'ball' end of those allen wrenches are not for high torque [as you discovered]. Loosen the bolt with the non-ball end first . . . then use the ball end for quick removal.

Miguelangel

+1, Also a strong industrial heater, or boiling oilve oil could heat it up..I say olive oil cause it needs a lower temperature 2 boil...

operator

Now you know why ball ends should only be used to start a bolt. Never to remove or to torque one down.

wethepeople

Very strong magnet?

Peek the Geek

Thanks for all of the suggestions so far. I feel a bit stupid, because I know I shouldn't have been using a ball-end wrench, but the correct hex was out in my garage, and I was a bit too lazy to just go up and get it.

Lesson learned.

As suggested, I did try tapping various sides with a punch and could pop one side up at a time, but never enough for it to come out or even have enough to grab with a needlenose.

Also, I can't cut a slot across the bolt with a dremel, because the bolt is recessed in the stem too far.

Perhaps I'll give the heat expansion method a try.

Peek the Geek

That was one of my first thoughts, but I didn't have a magnet strong enough. And by now, I've got the piece wedged in there tight enough that I don't think it would work.

Another thought I had was somehow gluing something to the broken ball and just pulling it out. Is there any type of glue that sets quickly and bonds well to steel?

dwood

P the G,

The 'heat' method is only effective on metals with different expansion rates: e.g. aluminum and steel. The broken allen wrench and the bolt are both steel.

If you have a dremel tool you should be able to take a pointed carbide cutter and work it gently around the hex cavity in the bolt head . . . tapering it [bell-mouthing it]. eventually you will have enlarged it enough to let the broken wrench piece fall out.

There should be enough of the original socket in the bolt to use a standard allen wrench in it and remove the bolt. Replace the bolt with a new one.

Peek the Geek

Thanks, dwood, for saving me some wasted time with the heat method. I'll give the carbide cutter a go tomorrow, but is there much danger of damaging the hex cavity enough that I will no longer be able to use a hex wrench to remove the bolt?

mikejavo

The Dremel method may even vibrate it loose. Good luck.

dwood

P the G,

I suspect that the broken piece of allen wrench is trapped in the socket head screw by a slight amount of burring near the top of the screw. If you use a carbide rotary burr carefully around just the top of the screw . . . there will be plenty of depth for an allen wrench to remove the bolt.

BTW, the suggestions for using heat would apply if you were trying to remove a stuck steel bolt from an aluminum part. But I don't think you'll need to resort to that. Just use a proper allen wrench.

Keep us posted with your progress!

JPMacG

The type of glue to try is super glue, aka model airplane glue, aka cyanoacrylate (sp?). Use the thinnest stuff you can find, as that is the strongest. It can be purchased at model aircraft hobby stores. It has a short shelf life (around 6 months), so get fresh stuff, not what has been laying around in your toolbox for 5 years.

I acutally doubt it will work for you, but it is worth a try. I have removed parts using this glue in the past but those parts had a large gluing surfaces. Use the glue very sparingly, just put the smallest possible drop on the broken ball driver. I've seen machinists use super glue to hold down a part that is being milled. The glue can be tremendously strong, but the surfaces have to fit together perfectly to get strength.

Superglue can be removed with acetone.

BCRider

When you had the amount of torque on it that was able to bust it off like that you very likely twisted the ball end around in hex and deformed the hex enough that the ball is now sitting partially in its own pocket.

Knowing my superglues from model building I can tell you that for this use it ain't all that super and it is not going to hold well enough to get out past the deformations in the hex you produced.

I think you're stuck with dwood's suggestion to carefully grind away the upper part of the ball and open up the mouth of the socket in the screw until the last part of the ball can fall out. Then hopefully there is enough of the hex left to get a proper allen wrench in there and take out the bolt so you can replace it. If the hex is damaged enough that you can't do this then the right size EZ-Out may work or you can then drill out the head of the bolt.

It'll be a fussy bit of work and likely use up more than one of the little grinding stones that fits in there. The hardened allen ball will not allow you to use any cutting burrs so stick with the grinding points.

A hard lesson to learn isn't it.....

dwood

Small grinding stones will take forever . . . and many of them. A single 1/8" tungsten carbide burr with a point, mounted in a die grinder [or Dremel type tool] will do the work in about 1 minute. The piece of broken allen wrench will definitely come out.

Camilo

Get a very small drill bit and use your drill or dremmel to drill into the center of the stuck piece. If you slow your drill down as you're doing it, it will likely actually get stuck into the little piece. Pull it out with that. That would be my first choice.

Second choice, if that doesn't work, is to do the same, but after you get the tiny hole drilled, put a drop of super glue in it, put the drill bit back in, and let it set.

Matt Gaunt

You can't drill hardened steel like that, it just doesn't work. The bit will just slip off the end of the ball/bolt and likely cause damage to the OP's stem.

Richard_Rides

Turn it upside down and spray the hex ball with Freezing spray. Maybe it will fall out. Then again, maybe not.

waldowales

Unless it's in a blind hole, I would just drill the bolt out from the other side. There's a good chance the bit will stick, and screw the little bugger out.

BCRider

A carbide bit may work but from what I saw with the small carbide drills I've used it is more likely to shatter. The looseness of the ball rattling around will make that almost a certainty I would think. Carbide bits are extremely hard but they are also extremly brittle.

I've got a couple of true carbide burrs I use but I only use them on fiberglass where the normal HSS burrs wear out quickly.

I think you'll also find that on hardened steel like the ball end that the grinding bits cut quite fast.

facial

A steel-on-steel hammer blow, with hollow space for the ball head to fall out, might work with some oil. Hammers can produce very strong shock waves in steel - just don't put your finger in the way. This simple method was inspired by the fact that yesterday I had an mechanical pencil's eraser stuck in a pen cap. I tried fumbling with sophisticated ways, e.g., blowing on the end of the cap, but it turned out that a few dozen taps with the index finger is sufficient to nudge it loose.

But if you can't isolate the bolt itself, then it's no use hammering from the side as that will make the problem worse.

dwood

I agree . . . do not try to use a carbide drill bit. Use a carbide "burr" in a die grinder or other very high-speed tool [Dremel, e.g.]. The burr is available at Home Depot and other hardware stores.

The problem isn't that the bolt is too tight to remove. If the op had used the allen wrench properly this thread would not be necessary. Any attempt to drill out the allen bolt from the opposite end is silly and without the proper drill guide . . . very likely the drill will wander off the C/L and mess up the aluminum riser.

I've been fixing stuff like this in my machine shop for over 30 years, although I must admit not this exact problem. I assure you . . . with a die grinder and carbide burr . . . 60 seconds and you are done.

relyt

The bolt is likely a standard type of metric bolt. You might want to drill an EZ-out into the ball/bolt and remove the whole thing, sacrificing the bolt. Then go to the hardware store and pay 60 cents for a new bolt.

BCRider

He tried drilling the ball already. Wore out the bit. Dem ball ends are HARD!