carcassonne

I have to remove a screw whose hex head is completly worn. I.e. no allen key can hold a grip in there, the hole is completly round. How such a screw can be removed ? Any tip appreciated - thanks !

(sorry there's a typo in the title - can't edit it seemingly)

teamcompi

had the same thing happen a couple of months ago with a small 5mm water bottle bolt, I drilled a hole and used what is called an easy out, worked like a charm. I added a little grease when I reinstalled the new bolt so it wont happen again.

Best of luck

operator

Can you wrench it off with a vise grip? Could also hacksaw and use a flatblade screwdriver.

MudPie

This problem is not uncommon. One trick is to try a brand new allen wrench because of their new, sharp edges, but it sounds like you're beyond that. If the fastener stands proud, pliers could grip the head. Perhaps you can form a slot into the head and use a screwdriver to remove it.

If you want to invest in a set of screw extractors that don't need a pilot hole to be drilled, see:
https://www.sears.com/shc/s/p_10153_1...crew+extractor
I believe you can get cheaper set or lower cost brands, but the idea is the same. These also work great around the house.

Old Hammer Boy

Another option is to epoxy a sacrificial allen wrench to the bolt. Sometimes works, sometimes doesn't.

San Rensho 

Cut a slot or a notch in the head,then put a screw driver in the notch at an angle and hammer the srewdriver in a counterclockwise direction.

joe99

Unless the head is recessed, using vyce grips or cutting a slot as already suggested should work.

But if all else fails, choose a hex nut where the hole is almost the same size as the head of the damaged screw and place it on top of the head.

Take a wire feed (MIG) welder and aim into the hole in the nut being sure to hit the screw head first rather than the nut and fill the hole in the nut with weld.

Hopefully the nut will bond strongly enough to remove the screw.

The idea is that the nut should protect the bike from damage by the welding.

This is a "last resort" suggestion - please do not hold me responsible for any damage that does occur!

joe99

Another thought...

If you try using "Ezy-outs", be sure to use the correct size drill for the size of the screw. Some folk are inclined to use a larger drill in the hope of getting a better grip. But the trouble is if the remaining wall thickness is too thin, the taper of the Ezy-out can expand it and make the thread grip even tighter.

Also, be sure to use a proper Tee handle to turn the Ezy-out. Just putting an adjustable spanner on the driving square is asking for trouble in the form of a broken Ezy-out stuck in the hole.

Retro Grouch 

Allen wrenches don't last forever and they are cheap to replace. Probably what you really need to do to keep it from happening again is to replace your worn allen wrench. Why do so many people resist doing that?

Incidentally, you'd be surprised at how often a brand new allen wrench will remove a screw that you had thought was completely rounded out.

jsharr

I fixed your title. Use a dremel tool with cutting disc, or a hacksaw to cut a groove in the head of the screw and then use a screwdriver to back it out.

stringbreaker

Get the Sears things they work great

Old Dirt Hill

I've gone the epoxy/donor allen wrench route with success in the past.

hunyak

Use a sharp pointed center punch and hit it with a light hammer in a counterclockwise direction. I place the punch at 12 o'clock and and hammer it towards 9 o'clock, and keep going as necessary.

Seriously, a center punch works great for removing stripped and sheared bolts.

operator

yeah but you could also just take off the first 5mm of the hex wrench and get a brand new one without paying anything.

pj7

Probably too little too late, but I'll post this in case someone finds this thread while searching.
I had a stripped machine bolt on a piece of equipment here at work once. Nothing would get it out easily and the head of the bolt was recessed into the pan.
I just took another bolt and tack welded it to the head of the stripped out bolt with a MIG welder, then turned it on out.

OK, I'm done now.

wethepeople

I can't believe nobody mentioned tapping in a similar sized torx bit. It's never let me down.

Iowegian

+1 on the torx bit

pj7

Because firing up the MIG is more manly.
... and took about 10 seconds.

carcassonne

Thanks everyone for the suggestions and ideas!

I tried it today and no, I did not buy a MIG welding kit ;-) The screw was flush with the frame so there was no way to make a dent with a saw. Instead I took a small flat precision screwdriver, like the ones you can buy in a plastic case at the hardware store. The flat blade was just a bit larger than the diameter of the hole. I hammered it with care until it got some grip and then uses pliers to turn the screwdriver. This was a quite small screw, I don't it'd work with larger screws.

Thanks again for the replies.

Cheers.

kendall

+3 on the torx bit, use the cheap socket type and drive it in, seldom fails, though often not friendly to the torx bit.
another trick is to use an sae wrench on metric, and metric on sae, choose the next size up and bang it in, most metric sizes are so close to SEA that it's an interference fit and will sometimes rebroach the head so it -can- be reused, not advised though.

Ken.

mcbenney

+1 on the torx bit. My son's handlebar headset has been too low for years. Same problem with a recessed, stripped allen bolt. Took it to the local bike shop and they couldn't fix it (!!!). Found this post, tried the torx bit and it worked! I had to drive the bit into the allen bolt head with a hammer. Hard. But once it was well and truly wedged in, a careful turn of the wrench loosened the bolt. Thanks!

ZippyThePinhead

Similar problem; solved it by cutting a slot in the top of the allen screw with a dremel. Then we used a regular ol' flat-head screwdriver to extract it.

009jim

I've had previous success by cutting a slot for a flat screwdriver (i.e. use a hacksaw blade across the head of the bolt). As an added help, try using what I call an impact-driver, which is a type of screwdriver you hit with a hammer. I don't know if you can still buy them but they can be real useful in this sort of situation.

Pozharnik

All good, useful ideas. I had a stripped allen bolt on my Cinelli road stem. Couldn't get the angle to tap it, or use the ezy-out, so I used JB weld on a sacrificial allen wrench. After allowing the JB weld set up, the wrench would turn with a 'welded' grip on the stripped bolt. WALLA! Out came the stripped bolt. Just another 'tool' in the toolbox for your consideration. Happy cycling!