Worm Gear Bore Diameter 8 mm Bore Diameter Tolerance +/- 0.2 mm Bore Type Plain Face Width 30 mm Gear Shape W1 Hub Diameter 20 mm Material Stainless Steel Maximum Teeth Hardness 187 HB Metric Module Pitch 1.5 Number of Starts 1 Outside Diameter 28 mm Overall Length 40 mm Pitch Diameter 25 mm