I’ve been looking at getting some ACME threaded taps. I checked ebay without much luck. Here is the price from Leger (local Ottawa):
1 Pc 1/4”-20 NA Std. Acme hand tap $199.50
1 Pc 3/8”-12 NA Std. Acme hand tap $149.10
1 Pc 3/8”-10 NA Std. Acme hand tap $176.95
1 Pc 1/2”-10 NA Std. Acme hand tap $137.25
All ground for Delrin.
Not a pretty sight. Michael used heat to form some Ultra High Molecular Weight material around some ACME threaded rod. This seemed to give some very nice results. This could be a great answer to the problem.