Originally Posted by
lofter
could I rethread a pitch ten lockring? how expensive a job are you thinking it could be ?
First of all, is there enough material on the ID? If not it can't be rethreaded at all. If it is possible it won't be a cheap job, since you need to set up a screw cutting lathe with a metric lead screw to generate the thread. These days it could be done with a CNC lathe and a thread generating program, but the set up and programming time will be longer than the running time, and time is money on these machines.
If you're going to have one made, it's probably easier to start from scratch working on the end of a bar stock nub, boring the ID beyond the ring's thickness, threading that, turning the OD then parting it off. That has a complete lockring done in a single fixturing, except for the notches which can be added later.
It can be made from an air hardening grade of stainless steel, so you get a solid quality finished part. Unfortunately, it's probably cost about $100 or so.