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Remove a rounded out Allen bolt

Started by RB, May 06, 2008, 06:27:58 AM

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RB

Take a torx / star bit (buy a cheap-o set at horrible freight) that is slightly larger then the rounded allen socket you have destroyed. As straight as possible, drive (with a hammer) the torx / star bit into the bolt head until the bit has bottomed out (do not remove). Notice that the torx has cut new grooves. This maybe enough torture for the bolt to break loose with an appropriate size ratchet, but i found that a few good whacks with the hand (yes manual) impact was necessary before the ratchet.

RB

Count Desmo

Good tip!  Screw extractors can accomplish the same thing if you have them around.  It always helps to apply some "heat" to the bolt in question.  This can be done by tapping on the bolt with a ball peen hammer, or actually warming it up with a torch.  All of the regular warnings about paint and such apply.

RB

i have never had luck with extractors, and i always try them first. this method accomplishes two things.
1. Creating a good biting surface for force to be applied.
2. The pounding of the torx into the bolt and hand impact helps loosen the stiction where the head meets the material it is securing, which is usually th culprit.

This was from my triple bolts on my lower triples.

RB

Count Desmo

I had the same problem on the upper triple on an ST I had.  I used a MATCO short screw extractor and did what you described above.  With the screw extractor it helps to tap, then turn slightly, tap again, etc. etc.  I've never tried the Torx bit, though.

Popeye the Sailor

At times when I've been *really* desperate I have actually forced a metal object into the screw head.....



....then welded it to the screw. What can I say? It works. Don't melt anything important.
If the state had not cut funding for the mental institutions, this project could never have happened.

RB

welding....i had lent my welder to a friend that weekend...go figure.
On the same lines though...if you snap the head of a bolt off. take a washer and weld it to the bolt, filling in the hole like a rosette. Then fine a nut, and do the same on top of the washer. Wait a few seconds, and twist out easy with a wrench.

That may be one of my favorite tricks. You can forego the washer if the nut is shallow enough. Plus this concentrates heat where you want it.

RB

duckwrench13

You can also use a very small chisel or flat nosed punch.

First, line the chisel (or punch) up with one of the "corners" of the allen head. Give it a couple good solid taps to set a groove. Next, change the angle of the chisel so it will drive in a counterclockwise direction. Remember, lefty loosey....

A few good hits, and it should be loose enough to turn by hand. Or if it's in a slightly confined space, you can insert an appropriately sized flat blade screwdriver into the bolt head, and turn it out as normal.

If you've chiseled/punched it, and it doesn't want to budge, you may need to apply some heat. Just remember to heat the area around the bolt, not the bolt itself.

You can also try a Left-hand drill bit. The drill is designed to cut while turning left. As the drill bites in, it will often grab and turn the bolt loose.
Of all the things I've lost, I miss my mind the most.

Gettin' blow'd up sucks!
Combat Veteran, Operation Enduring Freedom, Afghanistan 2006-2007

TCK!


ScottRNelson

A center-punch also works on the outside of a stuck screw.  Pound a dent in the side with the punch so that you have something to push against, then angle the punch so that it will turn the screw the direction you want.  Usually a few taps is all that it takes.

I learned this years ago from the brother of a friend of mine.  He was working as a mechanic and I was trying to open the cases of a wrecked Kawasaki engine that I had.  I couldn't get two of the screws out.  The mechanic friend had both of the stuck screws loosened in less than half a minute.  No special screw extractors needed.
Scott R. Nelson, 2001 XR650L, 2020 KTM 790 Adv R, Meridian, ID

A.duc.H.duc.

Quote from: ScottRNelson on May 07, 2008, 05:54:33 PM
A center-punch also works on the outside of a stuck screw.  Pound a dent in the side with the punch so that you have something to push against, then angle the punch so that it will turn the screw the direction you want.  Usually a few taps is all that it takes.

I learned this years ago from the brother of a friend of mine.  He was working as a mechanic and I was trying to open the cases of a wrecked Kawasaki engine that I had.  I couldn't get two of the screws out.  The mechanic friend had both of the stuck screws loosened in less than half a minute.  No special screw extractors needed.

+1 on this, then again, a lot of older motor bolts will come off you just drill the head off the bolt.
"Listen, not a year goes by, not a year, that I don't hear about some escalator accident involving some bastard kid which could have easily been avoided had some parent - I don't care which one - but some parent conditioned him to fear and respect that escalator."

Research Monkey

If its aluminum or titanium you can take a small hand saw and saw down a section so that you can fit a flat head screwdriver in it.  This is probably the easiest method that i have used several times.

You can also drill it out... I used the above method because my drill bits weren't sharp? enough to drill through the screw.
2005 Ducati Monster 620 - The Daily ride -
2006 GSXR600 - The Track Whore -
2008 Nissan Titan - The Toy Hauler -

fasterblkduc

I'll reinforce what Ducwrench13 said...If you apply heat, do it to the area around the bolt, and not the bolt itself. If you heat the bolt itself, you can actually make it worse. Also, if you have a steel bolt into aluminum, heating is usually pointless, because it does not work well with aluminum. I have worked with hydraulic components for many, many years and have removed thousands of plugs, valve cartridges, and bolts from aluminum manifolds. The quickest and easiest way (if you have clearance), is to hit the head of the bolt with a couple of good wacks with a hammer, then put on your wrench and turn it out. If you have already rounded the head then using some of the methods mentioned above can be even more effective by hitting the bolt head first. This is effedtive 99% of the time.

On a side note, if you guys are having the problem on your fork clamps, then you are not using the correct torque. This will not only cause the problem that you are seeing but can also cause stiction in your forks and affect your forks working properly. That's one of the critical places where you should follow the specs for torque.
Atomic Racing
Zalusky Advanced Riding School Lead instructor
2010 partners:
Komodo Gear, Motorex, Studio299, Moto Primo, Caztek, Chickenhawk

fasterblkduc

Quote from: RB on May 06, 2008, 06:27:58 AM
Take a torx / star bit (buy a cheap-o set at horrible freight) that is slightly larger then the rounded allen socket you have destroyed. As straight as possible, drive (with a hammer) the torx / star bit into the bolt head until the bit has bottomed out (do not remove). Notice that the torx has cut new grooves. This maybe enough torture for the bolt to break loose with an appropriate size ratchet, but i found that a few good whacks with the hand (yes manual) impact was necessary before the ratchet.

RB

This is one of my favs too. But actually what you are referring to is a "rounded head" not "stripped" Stripped is what happens to the threads when they are actually stripped off of the bolt, usually from cross threading. I don't know if you care or not, just trying to help you out. ;)
Atomic Racing
Zalusky Advanced Riding School Lead instructor
2010 partners:
Komodo Gear, Motorex, Studio299, Moto Primo, Caztek, Chickenhawk

RB


fasterblkduc

Cool, I was trying to figure out how to type that and NOT sound like a jackass.  [laugh]
Atomic Racing
Zalusky Advanced Riding School Lead instructor
2010 partners:
Komodo Gear, Motorex, Studio299, Moto Primo, Caztek, Chickenhawk