We machine micro worm and spur gear sets for robotic joints, prosthetic hands and compact actuators. Tolerances held to ±0.005 mm, finishes to Ra 0.2–0.8 μm, and 100% inspection before the parts leave the floor.
A pair that measures fine on the bench can open up once the housing, bearing preload and thermal expansion enter the stack. You get lost motion at the output, and the control loop spends its time chasing position instead of holding it.
Soft flanks and a rough finish on the worm thread wipe the lubricant film. Wear debris then changes center distance, so torque ripple appears early and the actuator has to be re-tuned or replaced in the field.
A 0.4 mm module pair running at a few thousand rpm puts any pitch error straight into the audible band. Once the housing is closed and the cable bundle is tied down, the only fix left is re-cutting the gear, not adjusting the mount.
Thin webs, sharp root fillets and 0.2 mm rim thickness look fine in CAD. On the floor they chatter, burr or distort during heat treatment, so the first article never matches the model and the schedule slips a week at a time.
Gear quality is decided by the pair, the material and the inspection loop, in that order.
A worm drive only behaves when the thread and the wheel are produced against the same reference. We cut both members in one setup family, so lead angle, pressure angle and center distance stay consistent across the batch. When the design allows it, we lap the pair together and record the contact pattern before shipping.
For a multi-start right-hand worm running against a precision-cut spur or wheel, the numbers that matter are lead error, axial pitch and flank finish. We hold lead error tight enough that backlash after assembly lands where your stack analysis predicted, not 20 μm away from it.
Micro gearing usually pairs a hardened alloy steel worm with a high-strength brass or bronze wheel. That combination gives you a hard, wear-resistant thread and a wheel that can absorb misalignment and minor debris without spalling. We machine the worm, carburize or harden it, then finish the flanks so the case is not ground away.
Where the load is low and corrosion matters more, 303 or 17-4PH stainless is a reasonable choice for both members. It will not match the fatigue life of a carburized alloy pair, so we say so before quoting rather than after the first field failure.
Pick by load, ratio and duty cycle, not by what is cheapest to cut.
| Route | Typical use | Watch out for |
|---|---|---|
| Hardened alloy worm + brass wheel | Prosthetic hands, high pinch force | Needs lubrication and a sealed housing |
| Stainless worm + stainless wheel | Wet, cleanroom or low-load joints | Lower fatigue life at high torque |
| Single-start worm, high ratio | Slow, self-locking joints | Efficiency drops below 50 percent |
| Multi-start worm, low ratio | Fast, back-drivable axes | Backlash control is harder |
| Straight spur pair only | Inline gearboxes, no crossing axis | No self-locking, more noise |
Worm shafts, wheel blanks and housings cut on 127 machines, with 16 simultaneous 5-axis centers for contoured flanks and one-piece hubs.
Cold-formed splines and serrations on shafts up to 4,000 mm, which keeps grain flow intact and avoids the notch left by a cut spline.
Case depth controlled to the drawing, followed by a finish pass so the hardened flank still meets its lead and profile tolerance.
Spur, helical and worm members cut to module 0.3 and finer, with deburring done by hand on the small pitches.
Ultrasonic cleaning, tumbling, bead blasting and passivation. Plating and black oxide available for corrosion resistance.
100% inspection before shipment, with runout, lead and backlash data recorded and reports issued on request.
Numbers below are what we can hold in normal production, not best-case lab results.
| Item | Value | Note |
|---|---|---|
| General tolerance | ±0.005 mm | ±0.0002 in on small features |
| Fine finish | Ra 0.2–0.8 μm | Flank and journal surfaces |
| Standard finish | Ra 0.8–1.6 μm | Most housing bores |
| Maximum part size | 4,000 mm | Longest axis across the shop |
| Rotary table | Ø400 mm | For circular and indexed work |
| Order range | 1 to 10,000+ | No minimum order quantity |
| Quotation | Within 12 hours | Free DFM analysis included |
| First parts ship | 3–5 days | After drawing release |
The number on the drawing is the number we inspect to, on every part, not on a sample pulled from the top of the bin.
ISO 9001:2015, IATF 16949:2016, ISO 13485:2016 and ISO 27001:2022 cover automotive, medical and data handling requirements.
Send a drawing and a target quantity. You get a price and a manufacturability note within 12 hours, and production can start in 24.
One prototype pair or a 10,000-piece run go through the same inspection loop and the same documentation.
Raw material check, in-process monitoring and final inspection on every order. Reports come with the parts on request.
Across the work we have shipped, the share of orders that went out late sits below 2 percent.
Worm and spur pair driving a finger joint, sized next to a coin to show the working scale.
Multi-start worm sets for back-drivable axes where backlash has to stay inside the stack budget.
Small spur trains with rolled splines on the output shaft, kept light enough for a worn device.
Stainless worm and wheel sets for cleanroom duty, passivated and cleaned before packing.
We work down to module 0.3 and finer on worm and spur members, depending on the tooth count and the material. Below that, tooling availability sets the limit rather than the machine.
Send the tooth count, the outer diameter and the load. We will tell you whether the geometry can be cut and inspected before you commit to a design freeze.
Yes, for anything where backlash matters. Cutting both members against the same reference keeps lead angle and center distance consistent, and it lets us check the contact pattern before shipping.
If you only need a replacement wheel, we still need the mating worm dimensions or a sample, because a wheel cut to nominal rarely matches a worn thread.
Hardened alloy steel for the worm and a high-strength brass or bronze for the wheel covers most robotic and prosthetic duty. The hard thread resists wear and the softer wheel tolerates slight misalignment.
Choose stainless for both members only when corrosion or cleanroom rules outweigh fatigue life. At high torque, a stainless pair will not last as long as a carburized alloy one.
We harden first, then take a finish pass on the flanks so the case is not removed and the profile still meets its tolerance. Center distance and lead are checked against the drawing after that pass.
Backlash in the assembled unit also depends on your housing and bearing preload. Give us the stack-up and we can cut to suit it.
Ra 0.2–0.8 μm is achievable on flank and journal surfaces, and Ra 0.8–1.6 μm on most housing bores. The finer range takes more time and adds cost, so it is worth specifying only where the lubricant film needs it.
Deburring on module 0.5 and finer teeth is done by hand. That step matters more than most people expect on small pitches.
A 2D drawing or a 3D model with module, tooth count, pressure angle, helix direction and tolerance class. Add the material, the heat treatment, the finish and the quantity.
If the geometry is still open, send the load, the ratio and the envelope. Our DFM note comes back with the price inside 12 hours.
Yes. Uploads are handled as confidential, and we can sign a non-disclosure agreement before you send drawings. The agreement page is linked at the bottom of this page.
For programs with a controlled drawing set, tell us at the quote stage so the files stay inside that channel.
There is no minimum order quantity. A single prototype pair goes through the same raw material check, in-process monitoring and final inspection as a 10,000-piece run.
Tooling cost is the part that does not scale down, so a one-off pair carries more of it per piece than a production batch.
Upload the model with material, heat treatment and quantity. You get a quotation and manufacturability feedback within 12 hours, and production can start in 24.
12-hour quote100% inspectionNo minimum order quantityNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
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