01
Center distance drifts after assembly
Bore spacing on the housing is off by 0.03 mm, so the mesh sits too deep on one flank. Contact moves to the tip, load concentrates, and the wheel wears in a narrow band.
Gear & Transmission Components
What Are Worm Gears
A worm gear set is a screw thread driving a toothed wheel at 90°. It buys you large reduction ratios in a small envelope, and often holds position when the input stops. We machine the shafts, housings and wheels that go around them.
Ø400 mm rotary table±0.005 mm toleranceRa 0.8–1.6 μm finishes1 pc to 10,000+IATF 16949:2016ISO 9001:2015
15 yearsIn precision manufacturing
127High-precision CNC machines
±0.005 mmAchievable tolerance
3–5 daysTypical part shipping
Where worm drive projects go wrong
Four Problems We See on Worm Gear Housings
Most failures trace back to geometry, surface finish or lubrication, not to the gear teeth themselves.
02
Shaft runout shows up as noise
Turning between centers without a grinding pass leaves runout at 0.02 mm. At 1,500 rpm input you hear a whine that no lubricant change can fix.
03
Worn worm wheel is replaced, and the noise returns
A new wheel on a pitted shaft never seats. Sliding contact needs matched surface quality on both members, so a partial rebuild usually repeats the failure within weeks.
04
Self-locking was assumed, not verified
Below a certain lead angle the drive holds on its own; above it, back-driving is normal. Teams that size the gearbox on ratio alone find the load creeping when the brake releases.
How we machine worm gear components
From Worm Shaft to Housing, Held to One Datum
Every bore, shoulder and bearing seat is cut against the same reference so the mesh lands where the drawing says it should.
Turning and milling
Worm shafts turned and ground in one setup
Worm shafts carry a helical thread, two bearing journals and usually a coupling feature. Any stack-up between those features tilts the mesh, so we cut the journals and the thread from one setup on a mill-turn center and keep the relationship tight.
Where a ground finish is called out, we leave grinding stock and bring the thread and journals to Ra 0.2–0.8 μm. Sliding contact lives or dies on that surface. A polished flank runs cooler and carries more load than a turned one.
- 1Thread formsTrapezoidal, acme, square and custom profiles cut to drawing.
- 2Runout controlJournals and thread held on a common axis.
- 3Materials1045, 4140, 17-4PH, 303 and 316 stainless.
Housing and wheel
Bores located from a single datum
A worm gearbox housing looks simple until you check center distance and axis squareness. We bore the worm axis and the wheel axis on a 5-axis center and measure the offset on the machine before the part comes off. That keeps center distance repeatable across a run instead of drifting part to part.
Worm wheels are often bought as a gear-cutting job, but the blank, the hub and the bore are ours. We turn the blank, cut the keyway or spline, and hold the bore to the pitch circle so the wheel runs true once it is pressed on.
- 1Axis squarenessWorm and wheel axes checked at 90° before release.
- 2Bore fitH7 and press fits held to ±0.005 mm where required.
- 3Lubrication featuresOil galleries, drain ports and seal seats machined in the same setup.
Selection guide
When a Worm Drive Fits, and When It Does Not
Use this to sanity-check the concept before you commit to tooling.
| Requirement | Worm gear set | Better alternative |
|---|---|---|
| Reduction above 20:1 in one stage | Yes, up to roughly 100:1 | Planetary or two-stage helical |
| Quiet running at low speed | Yes, sliding contact is quiet | Belt drive |
| High efficiency | No, typically 40–90% | Helical or planetary |
| Holding load with power off | Often, if lead angle is low | Brake plus spur gear |
| Compact 90° layout | Yes | Bevel gearbox |
| High input speed | Limited by heat and sliding | Helical gear set |
What we make
Machining Services for Worm Gear Assemblies
One supplier for the rotating parts, the housing and the finish.
01
5 Axis CNC Machining
Housings with angled bores, mounting pads and oil passages cut in one fixturing.
02
CNC Turning
Worm shafts, wheel blanks, spacers and bearing journals, with grinding stock left where needed.
03
CNC Milling
Flanges, covers, end plates and brackets that locate the bearing bores.
04
Rapid Prototyping
Fit-check housings and mock-up gear sets before you commit to production tooling.
05
Surface Finishing
Black oxide, electroless nickel, anodizing and bead blasting for wear and corrosion.
06
Assembly Support
Keyways, splines, press-fit bores and dowel holes machined to mate on your line.
Capability
Tolerances and Materials for Gear Components
Numbers you can design against.
| Parameter | Capability | Notes |
|---|---|---|
| General tolerance | ±0.005 mm | ±0.0002 in on critical features |
| Fine surface finish | Ra 0.2–0.8 μm | Ground worm threads and journals |
| As-machined finish | Ra 1.6–3.2 μm | Housing bores and covers |
| Maximum part size | 4,000 mm | Larger travel on request |
| Rotary work | Ø400 mm table | Angled and compound bores |
| Steels | 1045, 4140, 4340, 17-4PH | Case-hardening grades on request |
| Bronze and brass | C36000, C27400, C28000 | Worm wheel blanks |
| Inspection | 100% before shipment | Reports on request |
Why GreatLight
Numbers Behind the Parts
Fifteen years of cutting metal, and the equipment to keep it repeatable.
15Y
Manufacturing since 2011
Three wholly-owned plants in Dongguan and a factory in Singapore, covering 7,600 m² with 150 technicians.
127
CNC machines on the floor
16 simultaneous 5-axis centers, 16 mill-turn centers and 12 four-axis mills cover shafts, housings and one-off fixtures.
±0.005
Tolerance in millimeters
Held on bearing bores, center distances and journal diameters, with in-process checks before the part leaves the machine.
12 h
Quote and DFM turnaround
Send a drawing or STEP file and you get a quotation plus manufacturability notes within 12 hours.
24 h
To production start
Once the drawing is released, machining can begin within 24 hours.
< 2%
Historical late-delivery rate
Parts ship in 3–5 days on typical work, and late delivery has stayed under 2%.
7,600 m²Manufacturing space
150Technicians on staff
99.99%Qualification rate
No MOQFrom 1 pc to 10,000+
Industry requirements
What Each Sector Demands, and What We Deliver
Automotive & EV
Actuator housings and worm shafts for seat and window drives.
- IATF 16949:2016
- Ra 0.8–1.6 μm
Robotics & Automation
Compact gearbox housings with bores held square to one another.
- ±0.005 mm
- 100% inspection
Medical Devices
Small stainless worm drives for positioning mechanisms.
- ISO 13485:2016
- 303 / 316L
Industrial Machinery
Replacement worm wheels and shafts for legacy gearboxes.
- 1 pc minimum
- 3–5 day shipping
FAQs
Worm Gear Questions Engineers Ask Us
What is the difference between a worm gear and a worm wheel?
The worm is the screw-shaped input member, usually a hardened steel shaft with a helical thread. The worm wheel is the mating toothed disc, normally bronze or a bronze rim on a steel or cast iron hub.
They only work as a pair. The wheel's tooth form is cut to match the worm's thread, so mixing parts from different suppliers rarely produces a quiet mesh.
Can you machine a worm gear set to a lead angle I specify?
Yes, if you give us the lead angle, module or diametral pitch, number of starts and center distance. We cut the shaft thread and the wheel blank to those numbers.
Lead angle is the parameter that decides self-locking. Below roughly 5° the drive usually will not back-drive under load; above about 10° back-driving is expected. Confirm the value against your actual load case rather than the catalog chart alone.
Which material should the worm and the wheel be?
Hardened steel against bronze is the standard pairing for sliding contact. We machine worm shafts in 4140, 4340 or 17-4PH, and turn wheel blanks in C36000, C27400 or C28000 brass and bronze.
Putting two hardened steels together is a mistake in most worm drives. Without a dissimilar pair the flanks gall, especially at low speed and high torque.
How do you hold center distance on a gearbox housing?
Both axes are bored from one datum on a 5-axis center, and the offset is probed on the machine before the part is released. Bores are typically held to ±0.005 mm.
We can also leave a small stock allowance on the wheel bore so you shim the mesh on the assembly line. Tell us which approach your build uses.
What surface finish do worm threads need?
Ground threads at Ra 0.2–0.8 μm are the norm for anything running continuously. Turned threads at Ra 1.6–3.2 μm are acceptable for low-duty or intermittent drives.
Finish is not cosmetic here. A rougher flank carries a thinner oil film, runs hotter, and wears the bronze wheel faster.
Do you cut the gear teeth or only the blanks?
We machine the blanks, bores, keyways and splines. Hobbing and thread grinding are handled as part of the same production route so the blank and the tooth form come from one drawing revision.
If you already have a gear cutter, send us the blank dimensions and we will leave the bore and faces prepared for your process.
What is the smallest and largest worm shaft you can turn?
We run parts from a few millimeters up to 4,000 mm in maximum processing size, with a Ø400 mm rotary table for angled work.
The practical limit is usually stiffness, not envelope. Long, slender worms deflect during turning, so we plan support and light passes rather than pushing the size limit.
How fast can I get parts?
Quotation and DFM analysis come back within 12 hours, and production can start within 24 hours of drawing release. Typical parts ship in 3–5 days.
There is no minimum order quantity. One prototype worm shaft and a 10,000-piece run go through the same inspection route.
Send Us Your Worm Gear Drawing
Upload a STEP file or PDF and get a quotation with manufacturability notes within 12 hours. No minimum order quantity, and 100% inspection before shipment.
12-hour quote100% inspectionNo MOQNDA on request
