Repairing a damaged cone nut So I've got a nice hybrid bike that I picked up secondhand, was doing some maintenance on it to get it up and running and thought I'd replace the bearings in the rear axle.  In doing this, I've found a small pit in one of the cone nuts.

I don't have a picture, but this is the type of thing (In reality, mine's not as bad as this, it's less long and less deep):



Just thinking, would it be a really bad (or silly) idea to try to file the whole nut, so that the surface is smooth. I appreciate that this would be quite a lot of work to get right.

Cone nuts seem to vary so much and finding an exact replacement could be tricky, so thought I'd explore this idea...

Look forward to hearing your thoughts!
Unless you have a lathe the tolerances are going to be too high for you to be able to to do an acceptable job here.  Plus, I believe that the cone is surface hardened, after you grind through that the underlying material will be too soft.  If you visit your local bike shop they should be able to match it up.