Can I get some suggestions for removing stripped, over-tightened machine screws without damaging the screw holes?
March 13, 2010 8:23 AM   Subscribe

Can I get some suggestions for removing stripped, over-tightened machine screws without damaging the screw holes?

I've got a bike that came with cheapass disc brakes, which worked pretty well, but the spring that keeps the brake off by default on the front wheel recently broke. Being a cheapass setup, there's no way to actually fix that, so I'm left with having to replace the brakes. Fine. I've got a better set of brakes ready to go at this point. Here's where the problem crops up.

As I began to remove the screws that hold the brake disc onto the wheel hub, three of them have proven to be hellaciously over-tightened. I have not been able to remove them, and at this point they're stripped. I've applied the old standby, WD-40 to no avail. I've also cut a slot into one of the screws with a rotary cutting wheel so I could use a regular screwdriver instead of a torx. No dice. Those suckers are in there so tight that I'm coming close to breaking any screwdriver I try.

So, anyone have any brilliant ideas? I need to get the screws out cleanly so that I don't damage the threads on the hub, otherwise I'll have to get a new wheel.
posted by ursus_comiter to Home & Garden (15 answers total) 2 users marked this as a favorite
 
Can you grab onto the protruding head with a vice grip?
posted by chrisamiller at 8:26 AM on March 13, 2010


stripped? Use a rubber-band or if that doesn't work a latex glove between the screw-head and the screwdriver

Over-tightened? Good luck. Grease, WD-40, and some leverage. Seriously. I have had engine bolts be horrendously over-tightened before that I was able to get unstuck by putting a pipe on the end of the wrench, just so I could get an extra two feet over leverage.

Good luck
posted by zombieApoc at 8:36 AM on March 13, 2010


Best answer: There are tools for screw removal, like this.
posted by weapons-grade pandemonium at 8:41 AM on March 13, 2010 [1 favorite]


If you're willing to slot the screws with a grinder, maybe an offset screwdriver will offer more leverage? Otherwise you're drilling and tapping new threads...
posted by Max Power at 8:42 AM on March 13, 2010


If you need more leverage, put a screwdriver bit into a socket wrench. Use that in the slot you cut with the Dremel tool.
posted by fixedgear at 8:44 AM on March 13, 2010


Heat the aluminum hub with a propane torch.
posted by hortense at 9:31 AM on March 13, 2010


Nthing the "Grabit" screw remover W-GP linked above. Used to be a residential handy-monkey and I had a set of those in my kit. Work like a charm.
posted by Pirate-Bartender-Zombie-Monkey at 9:41 AM on March 13, 2010


Best answer: Heat the screw itself with a small torch, not the hub. Heating the screw will cause it to expand, yes, but this expansion, although it will temporarily work against you, will end up working in your favor because it will help break the mechanical bond to the threads. Heat plus a vise-grip will work.
posted by fake at 10:19 AM on March 13, 2010


nth the screw removal tools linked above. Works almost every time.
posted by jjb at 10:44 AM on March 13, 2010


yes, nthing the screw removal tool. among other jobs i've done, one of them was lightning-quick repairs of assembly mistakes at the end of a john deere vehicle assembly line. i always kept a set of those in my toolbox for broken off and stripped screws and bolts.
posted by TrialByMedia at 11:21 AM on March 13, 2010


A couple more home remedies before you go out an buy a screw extractor. Assuming aluminum hubs and steel studs: Ammonia will corrode aluminum oxide and may release the threads. Aluminum also has a higher coefficent of expansion than steel so try heating up the hub. Hair dryer or heat gun, not a torch, the annealing temp of aluminum is low.
posted by fair_game at 2:53 PM on March 13, 2010


Use real penetrating oil instead of WD40.
posted by Raybun at 3:09 PM on March 13, 2010


Worst case, drill them out, and re-tap-them to fit new machine screws. You could even take it to an auto body shop or mechanic. They deal with this sort of screws crap all the time, and will have the tools to get them out of there, or drill and re-tap.
posted by hungrysquirrels at 5:01 PM on March 13, 2010


And, you probably know this, but whenever you do get them out, be sure to grease up anything with threads you put onto the bike.
posted by hannahelastic at 7:07 PM on March 13, 2010


Response by poster: Problem solved thanks to Grabit, a blow dryer and elbow grease. Cheers all!
posted by ursus_comiter at 9:08 AM on March 25, 2010


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