plate and rings   solid steel, precision ground housing   cast aluminum with cooling fins housing diameter   4.2" (use adapters for smaller motors) surface finish   nickel plating vertical travel   5.5" (varies slightly with installation) bit openings   2", 2.625", and 3.75" columns   15/16" polished steel bushings   bronze height adjuster   0-1/8 scale with .0025" increments lead screw   8 tpi Acme precision rolled threads included tools   speed wrench/socket/fine adjuster options   Zero Clearance Insert, PC Guide Bushing Adapter, ProGuard empty weight   22 lbs. weight w/7518   34 lbs. ship weight   29 lbs.