Bevel gears are used as right angle drives where high efficiency is required. They are carried in stock as 1:1 to 6:1 ratios. Bevel gears are cut with the long and short addendum system and 20 deg pressure angle to compensate for tooth undercut in gears and pinions having low numbers of teeth. Most all of Martin bevel gears are cut with the coniflex tooth form to allow for a slight misalignment at assembly and during operation. Gears should be mounted at the correct distance from the core of apex center with thrust bearings being used in back of hubs to absorb the backward thrust created in this type of gearing. Martin Bevel Gear, Plain Reborable, Bevel Gear, 1 to 1.439 in Bore, 3.899 in OD, 2:1 Gear Ratio, 21 Teeth, 6 Diametral Pitch, 3-1/2 in Pitch Diameter, 1.05 in Face Width, No Screws Hub, 2-1/2 in Diameter Hub, 1-1/4 in Hub Projection, 2-33/64 in Overall Length, 20 deg Pressure Angle, Steel