501A - Bright, Fractional, wire & letter sizes
500 - Black Oxide, Metric sizes
501 - Black Oxide, Fractional, wire & letter sizes
6501 - Aircraft, Fractional, wire & letter sizes
6520 - Cobalt, Metric sizes
501P - Tin Coated, Fractional & wire sizes
520P - Tin Coated G Standard, Metric sizes
517P - Tin Coated Parabolic, Fractional & wire sizes
581 - M35 Cobalt Bright Oil Hole, Fractional sizes