Ground Helical Gear Bore Diameter 10 mm Bore Diameter Tolerance H7 Face Width 8 mm Finish Black Oxide Gear Shape S1 Gear Type Helical Hub Diameter 25 mm Hub Projection 10 mm Material Alloy Steel Maximum Teeth Hardness 60 HRC Metric Module Pitch 1 Minimum Teeth Hardness 50 HRC Number of Teeth 30 Outside Diameter 32 mm Overall Length 18 mm