Miniature Gears | Small Module & Micro Gear Supplier

Name: Miniature Precision Gears
Brand: Yujiaxin Tech

Small module spur, helical and worm gears from module 0.2 to 1.5 mm, held to DIN grade 7 to 9 for micro gearboxes, instruments and compact drive units.

Category	Mechanical Components
Materials	Brass H62, 20CrMnTi, 304 Stainless Steel, POM
Industries	Industrial, Automotive, Consumer Electronics, Medical

Send your drawing or 3D model — engineering review and quotation within 24 hours.

Yujiaxin Tech supplies miniature precision gears for compact drive units, instruments and micro gearboxes. Every gear is produced to the customer drawing, with module, tooth count, bore and backlash agreed before a quotation is issued.

What counts as a miniature gear

Module is pitch diameter divided by tooth count, expressed in millimetres. A gear with module 0.5 and 20 teeth has a 10 mm pitch diameter and an 11 mm outside diameter, so the whole part fits under a fingernail.

Most small module gears we quote sit between module 0.2 and module 1.5. At this scale tooth thickness, bore position and runout decide whether a drive runs quietly, and a few microns of eccentricity is enough to make it audible.

Gear types

A miniature drive usually combines several tooth forms in one housing, so a single project often contains more than one gear type.

Type	Typical use	Notes
Miniature spur gear	Single stage reduction, encoder wheels	Simplest to inspect, lowest cost per piece
Miniature helical gear	Quieter multi stage gearboxes	Helix angle must match across the pair
Worm and worm wheel	High reduction in a small envelope	Self locking depends on lead angle
Internal ring gear	Planetary stages, hollow shaft drives	Tooth access limits inspection
Cluster or stepped gear	Two ratios on one shaft	Concentricity between tooth sets is critical

Materials

Material on a small gear is chosen for load, duty cycle and noise target rather than cost alone. Brass runs quietly against a steel pinion and dominates instrument drives, alloy steel appears where torque is higher, and engineering plastics suit dry running low load parts.

Material	Why it is chosen	Watch out for
Brass H62 / C36000	Quiet running, good dimensional stability, low unit cost	Lower strength, not for high torque stages
20CrMnTi alloy steel	Tough core with a wear resistant surface after heat treatment	Distortion after treatment must be allowed for
304 / 316L stainless	Corrosion resistance for humid or cleaned assemblies	Higher unit cost than brass at the same module
POM / PEEK	Dry running, low weight, low noise	Thermal expansion shifts backlash
Titanium Ti-6Al-4V	Low mass for high speed or portable devices	Galling risk against similar metals

Typical specifications

Parameter	Typical range
Module	0.2 to 1.5 mm
Number of teeth	6 to 120
Outside diameter	2 to 40 mm
Bore diameter	0.5 to 8 mm, or plain shaft with no bore
Face width	0.5 to 8 mm
Pressure angle	20 degrees standard, 14.5 degrees on request
Accuracy grade	DIN 3962 grade 7 to 9, AGMA Q10 to Q12
Total composite deviation	20 to 60 microns depending on module and grade
Radial runout	0.010 to 0.030 mm
Backlash in a matched pair	0.02 to 0.08 mm
Tooth flank roughness	Ra 0.4 microns or finer

These are the ranges we quote most often for miniature gears. Final values are fixed by your drawing and by the housing the gear has to fit.

Accuracy grades

DIN 3962 and AGMA 2000 group gear accuracy into numbered grades, and the difference shows up as noise and transmission error. Grade 9 suits a mechanism that runs occasionally, grade 8 covers most consumer and instrument drives, and grade 7 is where medical, robotics and audio gearboxes usually land.

Grade 6 and finer are possible on small module parts, but inspection cost rises faster than part cost, so we recommend agreeing the grade against a measured functional requirement instead of specifying the tightest available number.

Inspection and documentation

Tooth form is checked on a double flank composite tester, which rolls the part against a master and records total composite deviation and runout in one pass. Profile and lead measurements are added when the drawing calls out a specific grade.

Yujiaxin Tech operates to ISO 9001 and GJB 9001C-2017 quality systems. Shipments can include material certificates, dimensional reports, composite deviation charts and first article inspection data. These gears are supplied as components for your own assembly and approval.

Applications

Micro gearmotors and planetary gearheads
Surgical handpieces and dental instruments
Camera lens drives and optical mounts
Robotic joints and drone actuators
Metering devices, locks and office equipment

What to send for a quotation

2D drawing or 3D model with module, tooth count, pressure angle and helix angle
Accuracy grade, or the noise and backlash limits the assembly must meet
Material grade, and whether a mating pinion is part of the scope
Bore, keyway or shaft details, and any hub or web features
Estimated annual volume, and whether prototypes are needed first

FAQ

Can you produce a gear with fewer than 10 teeth?

Yes, but undercut becomes the limiting factor. Below about 17 teeth on a 20 degree pressure angle the drawing usually needs profile shift to avoid a weakened root. Send the tooth count and we confirm the shifted profile before quoting.

Do you supply the mating pinion as well?

A gear pair should be quoted together, because backlash, center distance and helix angle are defined by the pair rather than by one part. Supplying both also removes the risk of two suppliers working to slightly different reference dimensions.

How small can the bore on a micro gear be?

Bores down to 0.5 mm are practical in brass and stainless. Below that, a plain shaft with no bore or a D shaped flat is usually the better design, because the wall under the root becomes the weak point.

What is the minimum order quantity?

Miniature gears are quoted per project rather than from a catalogue. Prototype batches of a few dozen pieces are available, and unit price falls as annual volume grows.

Browse the full mechanical components range, review the materials we work with, or send us your drawing for a small module or micro gear quotation.

Miniature Precision Gears