ANSI .74 X 1.5 CAT40 M16 X 2.0 Coolant Thru Retention Knob ~ TPI is M16 X 2.0. ~ Heat treated alloy steel hardened to HRC 52~56°. ~ ANSI/AMSE B5.50-1994. ~ Coolant thru. ~ L is 1.50 ~ L1 is .44 ~ L2 is .13 ~ D is .94 ~ d1 is .74 ~ d2 is .49 ~ d3 is .28 ~ A is 45°. TPI is M16 X 2.0. Heat treated alloy steel hardened to HRC 52~56°. ANSI/AMSE B5.50-1994.