Chainsaw Repair

If you are going to turn new inserts on a lathe  if you cut a slight interference thread they won't back out .Don't get too carried away because what you're actually doing is reforming the hole thread .Too much interference you could make yourself more trouble than you already have .

They also make some factory made inserts which have serrated teeth in the bottom which once set hold pretty good .You'll have to Google it because I can't remember exactly who made them .Mc Master -Carr might carry them for all I know .Keep in mind if you stay with steel there's less chance of screwing up the internal threads than with aluminum .It takes just the bolt diameter for depth of threads on steel to get full holding power .Double on cast iron and about 4 times on aluminum .Trivia 101 .