I bought a trailer hitch, knowing it didn't come with the bolts, not realizing just how difficult it would be to find new bolts. I ordered some online, and they arrived and I realized I missed the warnings about getting one with threads all the way up to the head. The bolts I recieved only have thread a couple of inches up, not far enough up to reach where the threads on the original shorter bolt went.

I talked to the sales rep from the company I ordered them from. He has none with more thread. I said I might try to run a die up on it and he said that he was no engineer, but that he understood doing so would weaken it.

I called another company, and they do not have bolts with that much thread either. I asked this guy about using the die, and he said that it would work, but that it would create an imperfect thread at the point where the original thread and the new thread met up, that this would be visible. But he said that it would be just as strong and would run through nuts just as well, it was just a cosmetic thing that they don't do because buyers would find them unacceptable. He sounded more confident of his position than the other guy, but he could be wrong.

The first guy said that the bolt's threads were rolled on, not cut, and that cutting threads would weaken the bolt because of it cutting through the grain of the metal (or something like that). He had no idea just how much weaker this would make the bolt, only slightly or greatly.

So I don't know if there are any metallurgists or engineers reading this, but if so, I would appreciate your opinions. The bolt is a steel grade 8.8 hex cap screw, M14 x 2.0 x 130mm. The thread goes about two inches from the end, and I would need to add another two inches of thread.