HEMCOChrome™ Process- unconditionally guaranteed against chipping
All gages conform to ANSI B47.1
L1 Plug classifies the thread as to "Maximum", "Basic" or "Minimum"
L3 Plug must match the classification of the L1 plug within +/- 1/2 turns
6-Step Crest Check Plug: When the L1 plug is at the maximum notch, the 6-step gage must go between "MX" and "MXT" notch. When the L1 plug is at the Basic Notch, the 6-Step Gage must go between "B" and "BT" notch. When the L1 plug is at minimum notch, the 6-Step Gage must go between the "MN" and "MNT" notches.