Ground Machined Worm Bore Diameter Not Applicable Bore Diameter Tolerance Not Applicable Bore Type Not Applicable Face Width 30 mm Finish Black Oxide Gear Shape W6 Hub Diameter Not Applicable Hub Projection Not Applicable Material Alloy Steel Maximum Teeth Hardness 60 HRC Metric Module Pitch 1 Minimum Teeth Hardness 50 HRC Number of Starts 2 Outside Diameter 18 mm Overall Length 140 mm Pitch Diameter 16 mm