Screw Gear Bore Diameter 20 mm Bore Diameter Tolerance H7 Bore Type Plain Face Width 25 mm Finish Black Oxide Gear Shape S1 Gear Type Screw Hub Diameter 50 mm Hub Projection 18 mm Material Carbon Steel Maximum Teeth Hardness 194 HB Metric Module Pitch 3 Number of Teeth 15 Outside Diameter 69.64 mm Overall Length 43 mm