Brass Worm Wheel – M0.5, 20T, Complete Set with Worm Shaft

A brass worm wheel is the driven gear in a miniature worm gear pair — the worm wheel mates with a worm shaft to form a complete worm transmission. The combination of a worm wheel and worm are the components of a worm gear. A worm gear is a staggered-shaft gear that creates motion between shafts using threads cut into a cylindrical bar, providing speed reduction determined by the number of worm threads and the number of teeth on the worm wheel. Korea Ever-Power's standard brass worm wheel set includes one M0.5 modulus brass worm shaft (Z1 = 1 start) and one 20-tooth brass worm wheel — together forming a complete 20:1 worm gear pair in a miniature, lightweight, corrosion-resistant package.

Korea Ever-Power's brass worm wheel sets feature simple, compact structure; long service life through high-quality brass material; high transmission ratios of i = 10–80 in one stage; and precision hobbing on NC gear hobbing machines. Packing: oil paper / poly bag / box (inner); wooden case or pallet (outer); custom packing available. Payment: L/C, D/A, D/P, T/T, Western Union, Money Gram, PayPal. 30-day after-sales service. Lead time 15+ days.

General Specifications

Worm Wheel Dimensions

Worm Shaft Dimensions

① Complete Set: Worm Shaft + Worm Wheel

Each Korea Ever-Power brass worm wheel set includes one M0.5 modulus brass worm shaft (Z1 = 1 start, OD 9.8 mm, height 20 mm, bore 3.17 mm) and one 20-tooth brass worm wheel (OD 11 mm, height 12 mm, bore 4 mm). Supplied as a matched, tested pair — the worm shaft thread and worm wheel tooth are hobbed to mesh together correctly, so the customer receives a confirmed worm gear pair rather than two independently produced components whose mesh must be verified before assembly.

② Simple, Compact, Lightweight Structure

The worm shaft transmission structure achieves 20:1 reduction in a package occupying a volume of approximately 20 × 11 × 11 mm — smaller than a typical sugar cube. Brass density (8.5 g/cm³) is lower than steel, and the total set weight of 16 g makes this the lightest complete worm gear pair at this module and ratio. The simple two-component structure (shaft + wheel) and right-angle output arrangement make brass worm wheel sets the standard for space-constrained miniature drive applications in instruments, consumer electronics, and medical devices.

③ Large Transmission Ratio — i = 10 to 80

With Z1 = 1 (single-start worm), the transmission ratio equals the number of worm wheel teeth: a 20-tooth worm wheel gives 20:1; a 40-tooth worm wheel gives 40:1; up to 80-tooth wheels produce 80:1 — all in a single stage. This range spans the full requirement of consumer electronics and instrument drive applications where spur gear multi-stage alternatives would require 3–4 gear pairs, additional shafts, and 3–4× the volume to achieve the same ratio.

④ High-Quality Brass Material — Long Service Life

Brass is the standard worm wheel material for miniature light-duty worm drives. Its properties make it ideal for this application: excellent machinability (enabling precision hobbing at M0.5 without burring or tool deflection); good self-lubrication (the brass matrix retains oil and provides boundary lubrication at the mesh even when the lubricant film is thin); inherent corrosion resistance (no rust, no surface treatment required for normal environments); and good conformability (brass yields slightly under contact stress during run-in, improving the actual contact area).

⑤ Precision NC Hobbing — Consistent Quality

Korea Ever-Power produces brass worm wheels and worm shafts on NC gear hobbing machines (NC gear hobbers, NC gear shapers, NC lathes, NC gear shaving machines, NC gear milling, NC gear grinding). NC hobbing ensures consistent tooth spacing (pitch error), tooth profile form, and lead angle — the three accuracy parameters that determine worm gear noise, efficiency, and contact pattern quality. Each production batch is inspected against drawing specifications before packing, ensuring that every set delivered performs to the stated 20:1 ratio at the rated torque capacity.

Speed Reduction Mechanism

Speed reduction is determined by the ratio of worm threads to worm wheel teeth: i = Z_wheel / Z_worm. For this set: i = 20 / 1 = 20. This means the worm shaft rotates 20 times for every single revolution of the worm wheel output. If the motor drives the worm at 600 RPM, the output at the worm wheel shaft is 600 / 20 = 30 RPM — with the output torque (less friction losses) multiplied by 20. The torque multiplication is the primary reason the worm gear pair is used in miniature actuators where a small stepping motor drives a low-speed, high-torque output axis.

Worm Wheel Tooth Geometry

The worm wheel tooth is not straight — it is curved in the axial direction (a globoid or enveloping form) to wrap around the worm thread and achieve line contact rather than point contact. The 11.2 mm tooth diameter (versus the 11 mm OD of the wheel body) reflects the addendum circle that extends beyond the worm wheel OD at the tooth tip. The 4 mm bore (hub hole) is sized for the output shaft of the stepping motor or instrument drive — the worm wheel is typically press-fitted or adhesive-bonded to the output shaft in miniature instrument drives.

Worm Shaft Bore (Inner Diameter)

The worm shaft inner diameter of 3.17 mm (0.125 in = 1/8 in) is sized to fit the standard shaft diameter of common miniature motors — including small DC gear motors and stepper motors with 3 mm or 3.17 mm output shafts. The worm mounts on the motor shaft by press fit, loctite adhesive, or a set-screw arrangement depending on the torque level. The 3.17 mm ID matches the 1/8 inch shaft common in North American and European miniature motor standards, making this brass worm wheel set directly compatible with the widest range of motor suppliers.

Why Brass for the Worm Wheel?

In worm gearing, the worm wheel material is always softer than the worm shaft material. This deliberate hardness differential means that when contact fatigue wear eventually does occur in service, it occurs on the worm wheel (the replaceable component) rather than the harder and more expensive worm shaft. For miniature drives where the worm shaft is integral with the motor drive shaft, this material strategy is essential — the brass worm wheel must wear before the steel motor shaft worm to keep maintenance cost low and motor life long.

Precision Instruments

M0.5 brass worm wheel sets in theodolite azimuth and elevation drives, coordinate measuring machine probe drives, and oscilloscope probe positioning mechanisms. The miniature size, light weight (16 g complete set), and precise 20:1 ratio in a right-angle arrangement make this worm wheel set the standard drive element for precision instrument positioning drives where accuracy and compact size are the primary requirements.

Miniature Robots and Actuators

M0.5 brass worm wheel sets as the final reduction stage in miniature robotic finger joints, educational robot servo drives, and hobby robot arm joints. The self-locking property (single-start worm at M0.5 has a lead angle below the friction angle) holds the joint position without motor power — essential for battery-powered portable robots where holding current would drain the battery.

Medical Devices

M0.5 brass worm wheel sets in infusion pump rate-setting drives, portable medical device joint drives, and diagnostic instrument positioning mechanisms. Brass is non-magnetic, non-sparking, and compatible with medical sterilisation environments (EtO sterilisation). The 30-day after-sales service and quality inspection records supplied with each Korea Ever-Power brass worm wheel set support medical device quality system documentation requirements.

Consumer Electronics and Toys

M0.5 brass worm wheel sets in remote-controlled toy vehicle steering drives, hobby servo mechanisms, and consumer electronics motorised adjustment drives. The complete set weight of 16 g and the compact physical envelope (20 × 11 × 11 mm combined) fit within the tight weight and space budgets of consumer electronics and toys, while the brass material's durability provides longer life than plastic worm gears at the same module.

Camera and Optical Equipment

M0.5 brass worm wheel sets in motorised camera platform pan/tilt drives, telescope focuser drives, and optical equipment positioning mechanisms. The worm gear's self-locking holds the camera angle or telescope focus position without motor power — preventing drift and eliminating the need for a magnetic brake or locking mechanism in battery-powered telescope and camera platform drives.

General Light Industry

M0.5–M2.0 brass worm wheel sets in valve position indicators, small conveyor indexing drives, and light-duty right-angle drive mechanisms. Brass worm wheels are often specified in light industrial applications where the sliding contact of the worm mesh would cause excessive wear on a plastic worm wheel (too much load) but the load is not high enough to justify the higher cost of a tin bronze or steel worm wheel. Brass occupies the intermediate position between plastic and bronze in the worm wheel material hierarchy.

Does the brass worm wheel set include both the worm shaft and the worm wheel?

Yes — each Korea Ever-Power brass worm wheel set includes one M0.5 brass worm shaft (Z1 = 1, height 20 mm, OD 9.8 mm, ID 3.17 mm) and one 20-tooth M0.5 brass worm wheel (height 12 mm, OD 11 mm, bore 4 mm). The two components are produced as a matched pair to ensure correct mesh. Total set weight: 16 g. Packing: oil paper + poly bag + box inner; wooden case or pallet outer.

What payment methods are accepted for brass worm wheel orders?

Korea Ever-Power accepts L/C, D/A, D/P, T/T, Western Union, Money Gram, and PayPal for brass worm wheel orders. This broad range of payment terms is available because Korea Ever-Power is confident in its quality — we provide payment terms that other suppliers will not offer. After-sales service is provided within 30 days of receipt for any quality issues. For serious quality problems, appraisers are dispatched to confirm and negotiate compensation.

Can I order custom tooth counts or modules for the brass worm wheel?

Yes — Korea Ever-Power supplies brass worm wheel sets with transmission ratios i = 10–80 by varying the worm wheel tooth count from 10T to 80T with the same 1-start worm shaft. Custom modules are also available. The standard set is M0.5 / 20T / 20:1. To specify a different ratio, state the required ratio and Korea Ever-Power will supply the matching worm wheel tooth count and worm shaft starts. Send your requirements to Korea Ever-Power to begin.

"We build miniature camera platform pan/tilt drives and use M0.5 brass worm wheel sets from Korea Ever-Power. Set dimensions matched drawing specs within ±0.02 mm at incoming inspection. Self-locking confirmed — pan axis holds target angle within ±0.05° with motor off. 16 g total weight fits within our camera platform weight budget. PayPal payment accepted for our first small trial order — straightforward."

Kim Hyeon-jun  |  Optical Platform Mechanism Engineer, Seoul Precision Instruments Co.  ·  Q1 2026

"We distribute miniature drive components for hobbyist robotics. Korea Ever-Power's M0.5 brass worm wheel sets are the most dimensionally consistent of the four suppliers we've trialled. Bore-to-OD concentricity on the worm wheel within 0.03 mm across 50 pcs checked. 3.17 mm bore on worm shaft fits standard 1/8-inch motor shafts without reaming. Reorder turnaround under 18 days. No after-sales claims in 14 months of resale."

Lee Chan-ho  |  Miniature Components Distribution Manager, Gyeonggi Robotics Supply Co.  ·  Q4 2025

"We manufacture portable medical infusion pump rate-setting drives and specified M0.5 brass worm wheel sets from Korea Ever-Power. Non-magnetic confirmation and EtO sterilisation compatibility documented for our regulatory file. The 30-day after-sales service commitment is noted in our supplier qualification record. Brass material certified to composition — no nickel above trace levels, satisfying our allergy-sensitive patient population requirement."

Park Jae-won  |  Medical Device Mechanism Engineer, Busan Medical Devices Co.  ·  Q2 2026