Ground Helical Gear Bore Diameter 18 mm Bore Diameter Tolerance H7 Face Width 12 mm Finish Black Oxide Gear Shape S1 Gear Type Helical Hub Diameter 60 mm Hub Projection 12 mm Material Alloy Steel Maximum Teeth Hardness 60 HRC Metric Module Pitch 1.5 Minimum Teeth Hardness 50 HRC Number of Teeth 50 Outside Diameter 78 mm Overall Length 24 mm