Spiral Miter Gear Bore Diameter 12 mm Bore Diameter Tolerance +/- 0.2 mm Bore Type Plain Face Width 12 mm Finish Black Oxide For Shaft Angle 90 Degrees Gear Shape B3 Hub Diameter 45 mm Hub Projection 12.5 mm Material Carbon Steel Material Grade S45C Maximum Teeth Hardness 60 HRC Metric Module Pitch 2 Minimum Teeth Hardness 50 HRC