Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When a gear slips, strips, or runs rough under load, the whole machine pays the price. Engineers, machinists, and serious hobbyists building CNC routers, robotic arms, conveyor systems, or custom gearboxes need a spur gear that holds its tooth profile under real torque — not one that deforms after a few hundred hours. These Module 3 spur gears are machined from 45# medium-carbon steel and sized for applications where dimensional accuracy and material toughness both matter.
Each gear is a single-piece 45# carbon steel spur gear with a Module (pitch) of 3, a face width of 30 mm (approximately 1.18 in), and an outer diameter ranging from 36 mm (10 teeth) to 165 mm (53 teeth) — approximately 1.42 in to 6.50 in. Bore diameter varies by tooth count; see variant options for exact bore dimensions. The tooth profile follows standard involute geometry for smooth meshing with any mating Module 3 gear.
Typical use cases include open-frame CNC axis drives where a rack-and-pinion or gear-pair arrangement replaces a belt, rotary indexing tables in light machining fixtures, and custom speed-reduction stages in robotics or automation projects requiring a compact, rigid gear mesh.
| Material | 45# Medium-Carbon Steel |
|---|---|
| Module (Pitch) | 3 |
| Pressure Angle | 20° |
| Number of Teeth | 10 – 53 Teeth (see variant options) |
| Outer Diameter (OD) | 36 mm – 165 mm (1.42 in – 6.50 in) |
| Face Width (Thickness) | 30 mm (1.18 in) |
| Bore Diameter | See variant options |
| Tooth Profile | Standard Involute |
| Surface Finish | See variant options |
| Packing Quantity | 1 Pcs per order |
The tooth count determines both the gear ratio and the center distance between shafts. For a given gear ratio, divide the driven gear teeth by the driver gear teeth. Center distance equals (T1 + T2) × Module / 2, where T1 and T2 are the tooth counts of the two mating gears. Use the 36–165 mm OD range listed in the variants to confirm the gear physically fits your housing before ordering.
45# carbon steel has a typical tensile strength of 600–800 MPa. The 30 mm face width distributes tooth load across a wider contact area than thinner gears. Actual load capacity depends on operating speed, lubrication, and duty cycle. For continuous high-torque applications, consult standard gear-strength calculations (AGMA or ISO 6336) using the module, face width, and material properties provided.
45# carbon steel is not inherently corrosion resistant. For outdoor, humid, or washdown environments, apply a suitable lubricant or protective coating after installation. If corrosion resistance is a primary requirement, consider stainless steel or nylon gear alternatives for your application.
Yes — any two gears with the same module and pressure angle will mesh correctly regardless of tooth count or manufacturer. These gears use standard Module 3 / 20° pressure angle involute geometry, so they are interchangeable with other Module 3 spur gears. Confirm the center distance calculation matches your housing before assembly.
Bore diameter varies by tooth count — please refer to the variant options or contact us to confirm the bore for your selected tooth count. The bore can be enlarged by a machinist using a lathe or boring bar. Keyways and set-screw holes can also be added by a machine shop if your shaft requires them.
Yes. Carbon steel spur gears running under load require lubrication to reduce friction, prevent surface fatigue, and manage heat. A light gear oil or grease appropriate for the operating speed and load is recommended. Re-lubricate at regular intervals based on your duty cycle and operating environment.
Yes. Each variant is sold as 1 piece (1 Pcs), so you can order exactly the tooth count you need as a direct replacement. Match the module (3), pressure angle (20°), face width (30 mm), and tooth count to your existing gear to ensure a drop-in fit.
