Spur Gear, Metric Module Pitch 0.5, Bore Diameter 6 mm, Bore Type Plain, Hub Type Hub with Set Screws, Hub Diameter 22 mm, Hub Projection 7 mm, Face Width 5 mm, Pitch Diameter 25 mm, Finish Black Oxide, Material Carbon Steel, Pressure Angle 20 Degrees , Bore Diameter Tolerance H7, Gear Shape S1T, Includes Set Screw.