Stop in for a cup of coffee

from Engine Builder Mag..

Most OEMs and ring manufacturers specify a surface finish of 15 to 25 RA for moly faced rings, which can be achieved by finish honing with #280 grit stones. Cast iron and chrome rings can tolerate a somewhat rougher surface finish (20 to 35 RA), so coarser #220 grit stones can be used to produce this type of finish.

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