ANSI CAT50 X 45 Degree Retention Knob (M24 X 3.0) ~ Heat treated alloy steel hardened to HRC 52~56°. ~ ANSI/AMSE B5.50-1994. ~ L is 2.31". ~ L1 is .69". ~ L2 is 2". ~ D is 1.44". ~ D1 is 1.14". ~ D2 is .82". ~ ~ Thread is M24 X 3.0.