.59 X 2.24" CAT40 45 Degree 5/8"-11 Retention Knob ~ Heat treated alloy steel hardened to HRC 52~56°. ~ L is 2.24". ~ L1 is .98". ~ L2 is .24". ~ D is .91". ~ d1 is .59" ~ d2 is .39". ~ The thread is 5/8"-11.