How can i loosen a rusted bolt that won't budge when i try to get it off with a wrench?

Question

It's on the back wheel of a bicycle

Answer 1

A couple of people have suggested penetrating oil... that can be a good start.  If it is badly rusted, it can take several days with repeated applications, to work, and sometimes even that doesn't work.  Make sure that you are using the right sized box-end or socket wrench for best application of pressure to the nut, without ruining it (rounding it off).  You can also use a hammer-driven impact wrench (impact driver) with a socket or a long handled torque wrench with a socket to try to help break it loose.

If that hasn't worked after a week or so, you might try the GENTLE application of heat to the nut (not the axle) using a torch or perhaps a heat gun (torch is better - more concentrated).  The logic is to expand the nut, not the axle.  If you are using a box-end wrench, you can apply ice (to shrink) the axle while applying pressure to the heated nut.

If nothing else works, you can use a nut cracker/breaker (around $15 at Sears) to break the nut off.

In any case, I would replace the nut, or you are likely to have the problem again in the future.

Good luck and ride safe.

Tad

Answer 2

WD-40 or an air ratchet.

Answer 3

Buy a can of WD 40. Squirt it on and wait about 5 minutes.

Answer 4

WD-40, liquid wrench......