Matt O'Toole wrote:
> As was probably inevitable, the 8mm allen socket in my Shimano crank bolt is stripped. Any ideas
> on how to remove this bolt, other than drilling? How about banging in a Torx bit? Size? Anyone had
> to attack this problem recently?
>
> FWIW, these bolts may look neat but I think they're a bad idea. An 8mm allen isn't strong enough
> to stand up to the torque a crank bolt might need. The old 14mm standard head bolts were much more
> appropriate.
First try a _brand_new_ 8 mm Allen wrench. It is rare to have this problem except with worn tools.
One of the nice things about Allen wrenches is that they can be sharpened on a grinding wheel, just
grind off the worn-down end. (Make sure to quench in water frequently so the metal doesn't overheat
and get annealed.)
Unfortunately, even a nice fresh Allen wrench won't work once the socket is rounded out. I ran into
this once when this system first appeared.
The ultimate weapon is somethng called an "Easy-out." This is a tool that looks like a tapered tap
with a very steep left-hand thread.
See:
http://www.brokentap.com/easy-outs.html
The orthodox way to use Easy-outs is to drill a hole down the bore of the bolt, and then insert
the Easy-out.
In this case, however, I took a larger Easy-out, one that would have been too large to go into the
threaded part of the bolt. I got the largest size that will fit into the stripped Allen socket.
(Sorry, I can't recall what size that is.)
There is no Easy-out that comes in exactly the correct size for this, so the trick is to use the
slightly too-small size, and grind the point off until you get to the part that's thick enough.
Again, make sure to quench frequently.
Sheldon "I Don't Understand How Some People Manage To Live Without A Good Bench Grinder" Brown
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