Gerald had mentioned that any slippery plastic material could be used. We are not creating a lot of movement at this joint on the machine. Try it and see! :)

the HDPE materials are much more notch sensitive than PTFE... what this means is that a little nick can turn into a crack that spreads to the center and in the case of HDPE it can allow the wings to spread and continue to crack on the other side of the center hole until it splits in two. Teflon will not do this.

Anything slippery & stiff will do. Delrin, POM, Teflon, nylon... etc etc etc.

For what it's worth.... I'm using UHMW for the past....4+yr, still as good as new ;)

I have ordered quantities of UMHW as it comes close to the qualities of Teflon but is not quite as slippery and cannot take nearly as much heat. In the mechmate application UHMW's heat profile gives me the most concern. I will make some washers and try them.

No heat ( direct [friction] or indirect [environment] ) is a concern about this specific application here.
I've unmounted a number of time my tranys, therefore had chances to see if any wear & tear.....and...None.
As for slip"ness".....there maybe some difference (in theory from data sheet) may be interesting to evaluate, but what is the bottom..... "practical" line...for our usage ??

Amicalement, ;)

Robert, I tend to agree with you and sometimes I dive too deep in the specs :)