metric has he light knurl, sae has groove.I bought the SAE set today with 25% off coupon to compliment my metric Snap-On set. I was a little dissapointed at the lack of knurling on the SAE sets(shallow, semi-deep, and deep) while all the metric have knurling. I wonder what that is all about.
it done for identification . not best idea but that what get when copy rather than think/innovate a bit ...