HRCSG1821 - 21t 48p Hardened Steel Pinion Gear 1/8 Bore

This 21‑tooth 48 pitch pinion gear is CNC machined from hardened steel to provide durable, precision engagement with matching 48 DP spur gears in RC drivetrains. The 1/8″ (3.175 mm) bore fits standard 1/8 inch motor shafts commonly found in larger electric cars, trucks, and buggies, while a heavy‑duty 4 mm set screw secures the gear to the shaft for consistent mesh under load. Heat‑treated steel construction increases tooth surface hardness and fatigue resistance versus softer materials, making it suitable for high‑power brushless setups and frequent use scenarios. The tooth profile is cut to exacting tolerances for smooth power transfer and reduced drivetrain lash when paired with compatible spur gears. Typical face width and gear length are optimized to minimize interference with motor housings and to maintain correct spacing relative to the spur. Installation requires adjusting mesh and tightening with a hex driver, with optional thread locker for added retention in high‑vibration conditions. This gear is ideal for adjusting final drive ratios or replacing worn pinions in 48 DP systems.

• 21 tooth count matched to 48 DP spur gear systems for precise meshing
• hardened steel CNC machining for enhanced wear resistance and durability
• 1/8″ (3.175 mm) bore fits standard larger motor shafts
• heavy‑duty 4 mm set screw included for secure mounting
• optimized face width minimizes motor housing interference
• heat‑treated gear body increases surface hardness for longevity
• ideal for tuning gear ratios or replacing worn components in high‑power setups