Mel Bartels <mbartels@efn.org> said: >It is customary even in relatively good grit to have at the 20% >percentile, particles +-50% of stated size. I'm not sure what you're saying here. The way I would figure, 50% of stated size, starting from 46 micron, would be 69, while these things are more like 96 - over 100% larger. Jim L 1 John 5:13