Ground Machined Worm Bore Diameter 12 mm Bore Diameter Tolerance +/- 0.2 mm Bore Type Plain Face Width 32 mm Finish Black Oxide Gear Shape W3 Hub Diameter 25 mm Hub Projection 15 mm Material Carbon Steel Maximum Teeth Hardness 60 HRC Metric Module Pitch 2 Minimum Teeth Hardness 50 HRC Number of Starts 2 Outside Diameter 35 mm Overall Length 50 mm Pitch Diameter 31 mm