Criterion Boring Heads DBLs still made? | The Hobby ...
Nov 11, 2018· These bars leave a fine finish at the lower speeds boring heads require. Between 3/8" and 1/2", the lighter 3/8" bars will let you go slightly faster due to their lower mass. The DBL202 A heads take 3/8" bars; the 202 B head takes a 1/2" shank. I don''t use carbide tools in my boring heads.