3phase: Those are what I used, sourced locally from Motion Industries and IIRC were INA brand. I don't think Motion sells junk.
The top washer cracked and two pieces broke off one about 6mm, other 3x12mm and I suspect these broken pieces chewed up the needle bearing. AFAIK they were clean and well lubed. From your figures, it should have been ok. Hmmm.... More head scratching, at least they are cheap. I can't imagine heat being a problem in 1-2minutes operation at 10-20rpm. The washers are ground and sold with the bearings.