Material: Special brass CuZn37Mn3Al2PbSi/So. Pressure angle 15°. The gear wheels can only be used with worms having the same centre distance and the same transmission. * Worm only polished, worm gear with helical gearing. ** Worm with 9 mm hub diametre only. *** The figures stated for the efficiency are only reference values, since - besides the lead angle - also mounting, lubrication, speed and assembly have an influence on the efficiency.