K Thread Profile Full Length Gauge For Lh Screw, Required Size: Go- 55 X 6.35 Mm With 1 Mm Wear Limit, Thread Angle = 30 Degrees, Ref. Drg. No. Rdso- Sk- 79068 Alt-08 & Sk 99002 (Details). Materi Al Tool Steel. Is- 3748/90, Hardness- 50 / 55 Hrc. Supply With Calibration Certificate- Valid For Min. 01 Year Issued From Nabl Approved Lab [ Warranty Period: 30 Months After The Date Of Delivery ] ]