Spur Gear Metric Module Pitch 1.5 Bore Diameter 8 mm Bore Type Plain Hub Type Hub with Set Screws Hub Diameter 21 mm Hub Projection 15 mm Face Width 15 mm Pitch Diameter 18 mm Finish Black Oxide Material Carbon Steel Pressure Angle 20 Degrees Bore Diameter Tolerance H7 Gear Shape S3 Includes Set Screw