Pinion Gear Arrowmax AM-348012 — 48 DP, Bore Ø 3.175 mm, 12 Teeth

Arrowmax AM-348012 pinion gear is a precision-machined component for model drive trains designed to mesh with 48 DP (diametral pitch) spur gears. It has 12 teeth and a 3.175 mm (1/8") straight bore suitable for mounting directly on compatible motor shafts. The gear is intended for use where correct 48 DP engagement is required to maintain smooth, reliable power transmission in RC cars and other small electric models.

Advantages

This pinion gear offers accurate tooth geometry for consistent meshing with 48 DP gear sets and minimized backlash when paired with matching spur gears. The 3.175 mm bore ensures a secure, concentric fit on standard 1/8" motor shafts, and the 12-tooth count provides a balance between acceleration and top speed depending on the driven gearing. Manufactured by Arrowmax to dimensional tolerances appropriate for model applications, the gear supports reliable torque transfer and repeatable gear ratios.

Suitable for

• Electric RC cars and touring models using 48 DP gearing
• Small-scale electric vehicles and hobby projects requiring a 3.175 mm (1/8") motor shaft fit
• Repair or upgrade of model drive trains where a 12-tooth pinion is desired

Key specifications

• Tooth profile: 48 DP (diametral pitch) compatibility
• Number of teeth: 12
• Bore diameter: 3.175 mm (1/8")
• Shaft fit: straight bore for slip-fit or set-screw mounting (depending on motor shaft and coupling)
• Application: small electric drive trains for radio-controlled models

How to use

Mount the pinion gear onto the motor shaft aligning the bore with the shaft end; ensure the motor shaft and bore are clean and free of debris before installation. If the pinion is designed for set-screw fixation, position the gear so the set screw contacts the flat or keyed portion of the shaft and tighten to the manufacturer’s recommended torque to avoid slippage. For slip-fit applications, use appropriate retention methods such as a pinch hub, clamp, or thread-locking compound compatible with the materials involved. After installation, check gear mesh and backlash with the spur gear and adjust motor position or shims to achieve correct engagement without excessive force or binding.

Usage recommendations

Verify compatibility with existing spur gears by confirming 48 DP specification and match the 12-tooth count to the desired gear ratio. Periodically inspect the gear teeth for wear and ensure set screws or retention hardware remain secure; replace the pinion if tooth damage or uneven wear is observed to maintain smooth operation and prevent damage to mating gears.