Tips For Model A's

[Synchro909]

Originally Posted by Dan Partain

For those who haven't seen this before - To chase dirty or rusty threads, grind bolts with the same thread and run them into the holes that need cleaning. The sharp leading edge of the threads will do a pretty good job, and not ruin a good tap from grease/dirt combo. Regular hardware bolts work good for this and are cheap to replace when the threads get worn. I try to not use good A bolts if I can help it.

I've been doing this for years. Nowadays, I spend a little time getting the best edge on the treads as I can, then heat the bolt to bright red hot, almost yellow. Then drop it into a METAL container of oil.
This case hardens the bolt so long as it is a reasonable quality one in the first place and not one of those muck metal Chinese ones. You'll get much longer life out of it but makes sharpening it with a file pretty hard on the file (grind only).