Generate a spur gear STEP file from a description
A spur gear transmits rotation between parallel shafts. Teeth are cut straight across the face (parallel to the axis), which makes it the simplest and most common gear type — easy to manufacture, easy to inspect, and efficient at moderate speeds.
What it is used for
- Gearboxes and speed reducers
- 3D-printed mechanisms and robotics
- Timing and indexing drives
- Replacement gears for machinery
Dimensions that matter
| Number of teeth | Sets the ratio with its mating gear. 12 teeth is a practical minimum before undercutting. |
| Module | Tooth size in mm (pitch diameter ÷ teeth). Both gears in a pair must share a module. |
| Face width (thickness) | How wide the gear is. Wider spreads load but needs more material. |
| Bore diameter | The shaft hole. Add a keyway if the gear must transmit torque. |
What you get
A real solid model you can rotate and measure, plus downloadable STEP (machining and CAD), STL and 3MF (3D printing) and DXF (laser and waterjet) files. Optional built-in analysis covers stress (FEA), thermal, buckling, cost and manufacturability.
Before you see it, the built geometry is measured against the dimensions you stated, checked as a valid watertight solid, and — for assemblies — checked for interference. These are geometry and physics checks; they do not confirm the shape matches what you pictured, so review the 3D view or 2D drawing before relying on the part.
Previewing is free. Downloading is £2.99 per part, or unlimited on Pro (£29/month, £290/year).
Related parts
Common questions
What file formats do I get?
STEP, STL, 3MF and DXF — the formats CNC shops, laser cutters and 3D printers accept.
Can I change the dimensions afterwards?
Yes. Edit the numbers directly, or describe the change in plain English. Every edit is rebuilt and re-checked.
Do I need CAD experience?
No. Describe the part and its sizes in millimetres.
Is it free to try?
Yes — describing a part and viewing the 3D preview costs nothing.