1 Mod Small Gear 10T 12T 14T 16T Spur Gear With Screw 45# Steel 4/5/6/7mm Bore

Select your tooth count based on the gear ratio you need and the space available. A 10T pinion paired with a 20T gear gives a 2:1 reduction; a 14T pinion with a 28T gear gives the same ratio with a larger pitch diameter. Also check that the outside diameter (12–16 mm for this Mod 1 series) clears your housing walls and adjacent components before ordering.

Match the bore to your motor or drive shaft diameter. Common pairings: 4 mm or 5 mm for small DC hobby motors and micro steppers; 6 mm for standard NEMA 17 stepper shafts; 6.35 mm (1/4 in) for imperial-shaft motors common in RC and power-tool applications; 7 mm for larger DC motors. Measure your shaft with a calliper before selecting — a bore that is even 0.1 mm too small will not fit without machining.

Module (Mod) is the standardised metric tooth-size system. Mod 1 means the pitch diameter equals 1 × number of teeth (in mm). These gears mesh correctly with any standard Mod 1 spur gear, rack, or pinion with a matching 20° pressure angle. They are not compatible with Mod 0.5, Mod 1.5, Mod 2, or imperial DP gears.

The set-screw provides adequate holding force for the light-to-moderate torque levels typical of RC, robotics, and miniature CNC applications. For best results, ensure the shaft surface is clean and free of oil before tightening, and use a thread-locking compound (e.g. Loctite 243) on the set-screw threads. For high-torque or high-vibration environments, a flat on the shaft aligned with the set-screw significantly improves grip.

The machined 45# steel surface has a light protective treatment suitable for typical indoor workshop and RC environments. For outdoor use or high-humidity conditions, apply a light gear grease or anti-corrosion spray. If long-term outdoor exposure is required, consider stainless steel or engineering-plastic gear alternatives for your application.

Yes — any of these Mod 1 spur gears will drive a standard Mod 1 rack to convert rotary motion into linear motion. This is a common setup for pen plotters, mini CNC axis drives, and small linear actuators. Ensure the rack’s pressure angle matches (20°) and that the gear’s outside diameter clears the rack mounting surface.

Each order includes 1 piece. If you need a matched gear pair or multiple gears for a gear train, simply increase the quantity at checkout or place separate orders for different tooth counts and bore sizes to build your complete drive system.