{HEAD ~ Size deviation} can be measured as {TAIL ~ root mean square} of the diameter, with less than about 10% root mean square being preferred 
{ HEAD ~ Size deviation } can be measured as { TAIL ~ root mean square } of the diameter , with less than about 10 % root mean square being preferred
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH