HRNSG821 - 21t Steel 48p Pinion Gear 5mm or 1/8

This steel 48‑pitch pinion gear with 21 teeth is machined for high strength and precise tooth engagement on vehicles with a 48 DP spur gear setup. The bore is sized for a standard 5 mm motor shaft and includes an adapter sleeve to fit 1/8″ (3.17 mm) shafts for broader compatibility. Heat‑treated nitride steel construction increases surface hardness, wear resistance, and fatigue life compared to softer materials, making it suitable for both brushed and brushless motors in off‑road and on‑road applications. A 4 mm set screw secures the gear to the motor shaft with proper torque, helping maintain consistent mesh and reduce slippage under load. The gear’s tooth profile and pitch match common 48 DP spur gears for smooth power transfer. Its compact length maintains proper mesh clearance and minimizes interference with motor housings and chassis components. Installation requires only a hex driver to tighten the set screw after seating the gear on the shaft.

• 21‑tooth 48 DP steel pinion gear for matching 48 pitch spur gears
• nitride hardened steel boosts wear resistance and durability
• 5 mm bore with included 1/8″ shaft adapter sleeve for flexible motor fitment
• longer base surface for secure contact and reduced slip
• black finish compatible with a wide range of vehicles and motors
• 4 mm set screw included for firm mounting on motor shaft
• compact length maintains correct mesh and minimizes interference