Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
When a slipping or undersized gear stalls your CNC router, 3D printer, or robotics project mid-run, every minute of downtime costs you. Engineers, makers, and small-batch manufacturers who need reliable, dimensionally consistent motion-control parts turn to these 45# steel spur gears to keep their drives running without interruption.
Each gear is machined from 45# carbon steel and available in two module sizes — 1M (1 mod) and 1.5M (1.5 mod) — spanning 12 to 100 teeth. The 1M series features an outer diameter range of approximately 14 mm to 102 mm (0.55 in to 4.02 in), while the 1.5M series spans roughly 21 mm to 78 mm (0.83 in to 3.07 in) for the 12T–25T range. Bore diameter and keyway dimensions vary by tooth count; see variant options for exact figures.
These spur gears are well-suited for CNC axis drives requiring precise gear-ratio control, DIY robotic arm joints where torque transmission accuracy matters, and light industrial conveyor or indexing mechanisms that demand repeatable positioning. Long-tail use cases include 1 mod gear replacement for RepRap-style extruders, 45 steel spur gear for laser engraver Y-axis, and 1.5 mod transmission gear for automated sliding gate openers.
| Material | 45# Carbon Steel |
|---|---|
| Module Options | 1M (1 mod), 1.5M (1.5 mod) |
| Tooth Count Range | 12T – 100T (1M series); 12T – 25T (1.5M series, listed variants) |
| Pressure Angle | 20° (standard involute) |
| Outer Diameter (1M) | Approx. 14 mm – 102 mm (0.55 in – 4.02 in); see variant options |
| Outer Diameter (1.5M) | Approx. 21 mm – 40.5 mm (0.83 in – 1.59 in) for 12T–25T; see variant options |
| Bore Diameter | See variant options |
| Hub / Face Width | See variant options |
| Keyway | See variant options |
| Surface Finish | Machined steel, suitable for oil/grease lubrication |
| Sold As | 1 piece per order |
The module (M) defines the tooth size and pitch. A 1M gear has smaller teeth than a 1.5M gear of the same tooth count, making 1M suitable for lighter loads and compact drives (e.g., 3D printer extruders, small CNC axes), while 1.5M handles moderate torque applications like robotic joints or gate openers. Both modules must be matched — a 1M gear will not mesh correctly with a 1.5M gear.
Divide the driven gear tooth count by the driving gear tooth count to get your ratio. For example, pairing a 1M-20T pinion with a 1M-40T gear gives a 2:1 reduction. Use our full 12T–100T range to fine-tune ratios without custom machining. If you need both gears, add each variant separately to your cart.
45# carbon steel offers a tensile strength of approximately 600–700 MPa, making it appropriate for light-to-medium duty CNC and laser engraver axis applications at typical hobby and small-shop feed rates. For heavy-duty industrial cutting with high continuous torque, consider specifying your load requirements and consulting the gear's rated torque capacity based on face width and module.
45# steel is not stainless and will oxidize if left unprotected in humid environments. Applying a light coat of gear oil, grease, or a rust-inhibiting spray is recommended, especially for gears in semi-exposed or outdoor-adjacent installations. For fully enclosed gearboxes with regular lubrication, corrosion is not typically a concern under normal workshop conditions.
Bore diameter varies by tooth count and module. Please refer to the variant detail page or contact us to confirm the bore size for your specific Gear Model selection before ordering. If your shaft requires a custom bore or keyway, the 45# steel material is readily machinable by a local machine shop.
Yes. Standard metric racks in matching module (1M rack with 1M gear, 1.5M rack with 1.5M gear) will mesh correctly with these spur gears. Ensure the rack's pressure angle is also 20° to match the involute tooth profile of these gears. This makes them a practical choice for CNC gantry drives, linear actuators, and sliding gate mechanisms.
Each order is for one (1) individual gear corresponding to the Gear Model variant you select (e.g., 1M-20T = one 1 mod, 20-tooth gear). If your project requires a mating gear or multiple sizes, add each variant separately. Quantity pricing is not automatically applied — contact us for bulk order inquiries.
