Big thank you to Tom for registering, posting and generously offering advice (and sorry for my mistake).
I googled for Delrin suppliers and found a
Dutch (of course, they're always Dutch!) supplier who offers Delrin rods online, and it's not even expensive!
I know nothing about plastics, but it looks noteworthy that they call the stuff "
POM (Polyoxymethylene)/polyacetal/Delrin". Furthermore, in the technical explanation of POM properties they advise PETP (Arnite) for applications where the accuracy of POM is needed but also abrasive resistance, hardness and toughness of nylon. Arnite would be more suitable for precision parts under high dynamic stress.
J