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How do you remove a stripped hex screw from brakes?

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  • #16
    My first gambit on socket head screws (after using due circumspection: get penetrating oil/CRC to the backside threads if possible, NOT turning hard enough to distort or nearly strip the flutes)
    I'll take the good quality Allen socket on the side of the grinding wheel and grind the face until there's no radius at the intersections. The 90* edge actually sharp.
    Then, I'll judiciously whack the head of the fastener until it distorts a good deal, but not too much to hammer the sharpened socket into it. If it's a small/countersunk screw, I'll put a nice flat face on the appropriate drift and use that to distort the screw.
    In addition to giving really good bite to the tool/screw interface, , especially at the sharpened tip, I thing it also serves to help free the threads. The fastener, in addition to collapsing some, also must flex or distort the material under it to good effect, and the threads move or at least relax with each blow, freeing it somewhat and letting the penetrant in.
    Usually this is more than enough to get the fastener to release it's grip.
    If that fails, it may get nasty. Heat is usually the next step assuming I've had enough judgement to not overdo it and stretched the socket head.
    Then out comes the drill and center-punch and EZ outs.
    Wheelchairs, I guess they're generally too small for a Heli-Coil, but most of what I formerly did, they were.
    69yo male T12 complete since 1995
    NW NJ

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    • #17
      For smaller fasteners, if it gets to the point of drilling, I don't bother with EZ outs, too easy to snap off and then you're really screwed. I just keep drilling, carefully, and re-tap.

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      • #18
        Left hand drill bit then an easy out.

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        • #19
          We had the exact same problem. Tried all the tricks but ended up just taking an axel grinder to the unit that attaches the brakes to the chair. Worked like a charm and much quicker than the hours we spent trying to nicely get it off.

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          • #20
            Originally posted by rockbybay View Post
            We had the exact same problem. Tried all the tricks but ended up just taking an axel grinder to the unit that attaches the brakes to the chair. Worked like a charm and much quicker than the hours we spent trying to nicely get it off.
            in cases where you can do that and just replace the threaded fastener, that is usually the easy button-after a brief attempt using normal stuff.
            It also makes it easier to heat it without damaging what it's stuck in.
            Counterintuitively, you don't heat the nut or the piece the screw is stuck in. You heat the screw; it expands very powerfully in the part around it, crushing oxides inside and, perhaps, slightly enlarging the original threads. While cooling, quench with WD40 etc once it's below ignition temp and it usually becomes uber compliant.
            69yo male T12 complete since 1995
            NW NJ

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