wrote in message ...

I bought 0.015 thk round shim from McMasterCarr. I considered turning a thrust spacer but my inability to part off square and to tolerance means that I
would end up filing & lapping the thrust washer to tolerance (but probably not a uniform cross section). I really want a surface grinder or access to one.

You'll probably be fine, even if it does eventually end up in pieces in the bottom of the case...(which probably won't happen so long as it was properly heat treated for use as a thrust washer)

But in the future, I would suggest using a pair of spacers that are fairly close to one another in thickness rather than having one of them be thin enough that it might easily tear or crack in use.