RC4WD 20 TOOTH 32 PITCH STEEL PINION GEAR1x RC4WD 20 Tooth 32P Hardened Steel Pinion Gears Super strong, heat treated steel pinion gears! Heat treated hardened steel Engineered & Manufactured by RC4WD What's included: 1x RC4WD steel 20 tooth 32 pitch pinion gear 1x set screw What is heat treatment? Heat treatment is a technique for metals and alloys to "toughen". The metal is transformed from brittle martensite into bainite or ferrite. Precise control of time and temperature during the tempering (heat treatment) process are critical to achieve a metal with well balanced mechanical properties.