Power Tools Gears and Carbon Brush: 1. Suitable for BOSCH 20S hammer 2. ... factory is professional manufacturer of power tools, and matched spare parts: armatures, stators, aluminium casting, gears and carbon brush.Power Tools Gears and Carbon Brush:1. 100 ... 20CrMnTi4. Gear hardness is 53, as our tools all parts are the same hardness: armature shaft, gear, spindle. Power Tools Gears and Carbon Brush