Ground Machined Worm Bore Diameter 6 mm Bore Diameter Tolerance +/- 0.1 mm Bore Type Plain Face Width 20 mm Finish Black Oxide Gear Shape W2 Material Carbon Steel Maximum Teeth Hardness 194 HB Metric Module Pitch 1 Number of Set Screws 1 Number of Starts 1 Outside Diameter 18 mm Overall Length 32 mm Pitch Diameter 16 mm