BOSI Standardized Tap Tools of M22x2.5 HSS Steel Fast Normal Thread Taps It applied the material of 6542 HSS. its hardness is up to HRC622. It taps quickly, thread grinds accurately, and has long service life. Product Name: thread taps; Dimension: M22 Screw Pitch: 2.5mm; Material: 6542 HSS; weight:325g