Plastic Spur Gears – POM, Nylon, M0.1-M2.0, OD 2-100mm

Plastic spur gears are straight-toothed cylindrical gears produced in engineering thermoplastics — primarily Polyacetal (POM, also sold under the trade name Delrin) and Nylon (PA). They carry the same involute tooth form and 20° pressure angle as metal spur gears, and transmit power and motion between parallel shafts with the same kinematic properties — but add the material advantages of plastics: self-lubrication, electrical insulation, corrosion resistance, low inertia, and the ability to absorb shock without permanent deformation. Korea Ever-Power's plastic spur gear range covers module M0.1 to M2.0 and outer diameter Ø2.0 to Ø100.0 mm — the full range for instrument and light-industrial applications.

Korea Ever-Power produces plastic spur gears by both handmade (machined from rod or plate stock) and moulded methods. Handmade / machined production is available before mould commitment — a sample can be made from a drawing to verify the gear form in the application before the injection mould tool is ordered. Face width 2.0–10.0 mm. Standard bore sizes from Ø1.40 mm; fully custom per drawing.

Self-Lubrication

POM and Nylon spur gears run without external lubrication in light-duty applications. The material's low surface friction allows the gear pair to operate dry — a major advantage in sealed mechanisms (cameras, printers, toys) where adding grease would contaminate sensitive components or require impractical maintenance access.

Lower Noise Than Metal

Plastic has much higher internal damping than steel or brass. At the tooth engagement frequency, the vibration energy generated by the tooth impact is absorbed by the plastic material rather than transmitted as airborne noise. Plastic spur gears in consumer products (printers, household appliances) produce significantly less operating noise than equivalent metal spur gears, which is audible to end-users in quiet domestic environments.

Lightweight and Low Inertia

POM density is 1.41 g/cm³ vs steel at 7.85 g/cm³ — a plastic spur gear is approximately 80% lighter than an equivalent steel gear. In high-cycle start-stop drives (stepping motor drives, camera mechanisms), the low inertia of plastic gears reduces the motor torque required for acceleration and braking, allowing a smaller and less expensive motor to be specified.

Corrosion Resistance

POM and Nylon do not rust or oxidise. In humid environments, food-adjacent equipment, or washdown machinery where metal gears would corrode without protective coating, plastic spur gears maintain dimensional integrity and surface quality throughout their service life without any surface treatment.

Protects Mating Components

Plastic gears are softer than metal gears and will wear preferentially in a mixed plastic-metal gear pair. This wear-sacrificial property is intentional in applications such as toys and light-duty mechanisms — the plastic gear wears instead of damaging the more expensive metal or moulded housing part, and is designed as the easily-replaced service part.

Cost-Effective Tooling

The cost of tooling for spur gears is lower than for helical gears — a spur tooth form can be cut or moulded with simpler tooling. For small plastic spur gears in M0.1–M1 range, the tooling cost is modest relative to the production quantity — making it economically viable to produce custom non-standard gear forms that would be prohibitively expensive in metal at low volumes.

Printers and Office Equipment

POM spur gears M0.5–M1.0 in laser printer paper-feed drives, multifunction copier mechanisms, scanner carriage drives, and fax machine roller drives. Self-lubrication eliminates grease that would contaminate paper; low noise suits office environments.

Cameras and Optical Devices

POM spur gears M0.1–M0.5 in digital camera zoom mechanisms, DSLR aperture and focus drive gear trains, and CD-ROM / optical drive sled mechanisms. Low inertia suits the high-speed, low-torque optical drive motor and the compact lens barrel envelope.

Medical Equipment

POM or Nylon spur gears M0.5–M1.5 in infusion pump drives, diagnostic device actuators, and dental instrument gear trains. Corrosion resistance in autoclaved environments (POM up to 134°C cycle in stainless-cased mechanisms); no metal contamination risk in fluid-adjacent drives.

Stepping Motor and Automation Drives

POM spur gears M0.5–M2.0 in stepping motor reduction stages for positioning systems. High resolution and low backlash from a tight-tolerance plastic spur gear pair suits the precise positioning requirement. Low inertia plastic gears reduce the torque demand on the stepper motor at each step change.

Household Appliances and Vending

Nylon spur gears M1–M2 in kitchen appliance drives, vacuum cleaner brush roller drives, and vending machine dispensing mechanisms. Low cost, quiet operation, and no lubrication maintenance suit the sealed, long-service-interval household product design environment.

Watches, Toys, and Miniature Mechanisms

POM spur gears M0.1–M0.3 in miniature watch and clock mechanisms, toy gear trains, and novelty device drives. At this size range, plastic machining from POM rod stock achieves the required tooth accuracy without an injection mould — Korea Ever-Power's handmade / machined service covers these ultra-fine-pitch configurations.

Can I get a machined sample before committing to a mould?

Yes — Korea Ever-Power provides handmade / CNC machined samples from POM or Nylon bar stock before any injection mould is ordered. This allows the gear to be tested in the application and the drawing dimensions confirmed before the tooling investment. The machined sample may have slightly different surface finish from the moulded production part (moulded surfaces are smoother and more consistent), but the tooth geometry and bore fit are confirmed to the drawing. Machined sample lead time is shorter than moulded — contact us with the drawing to confirm the sample cost and lead time.

What is the maximum torque that a plastic spur gear can transmit?

The torque capacity of a plastic spur gear depends on the module, tooth count, face width, material, speed, and operating temperature. As a general guide, POM spur gears at M1.0, 20 teeth, 5 mm face width can transmit approximately 0.05–0.15 Nm continuously at room temperature and moderate speed. Torque capacity scales approximately with module² × face width. For applications above approximately 1–2 Nm, or at elevated temperatures above 60–70°C, metal spur gears should be considered instead. Korea Ever-Power's engineering team can assess the torque capacity for the specific configuration — send the module, tooth count, face width, operating speed, duty cycle, and temperature and we will advise on material selection.

Does moisture affect the bore diameter of Nylon spur gears in service?

Yes — Nylon (PA) absorbs moisture from the environment and expands slightly as it does so. A Nylon PA6 gear bore at 6.00 mm measured dry may increase to approximately 6.02–6.04 mm at equilibrium moisture content in a humid environment. This is typically not significant for light press or clearance fits, but should be considered for tight interference fits. POM has much lower moisture absorption (≈ 0.2% vs 1.5–3% for PA6) and is the preferred material where bore stability in varying humidity is required. If using Nylon gears, Korea Ever-Power can condition the gears at the specified humidity level before measuring and adjusting bore dimensions to account for the expected in-service moisture content.

Can plastic spur gears be used without lubrication?

Yes, within the rated load and speed envelope. POM and Nylon both have inherent lubricity — the material surface provides adequate lubrication at the tooth contact for light to moderate loads in dry conditions. Adding a small amount of compatible grease (silicone grease for POM; petroleum-based grease for Nylon in non-food applications) extends life in higher-load or higher-speed applications. For food-adjacent applications, food-grade PTFE-based dry spray lubricant is compatible with both POM and Nylon and does not contaminate the food contact zone.

What applications use plastic spur gears from Korea Ever-Power?

Korea Ever-Power's plastic spur gears meet all kinds of needs for laser printers, digital cameras, scanners, CD-ROMs, stepping motors, medical equipment, vending machines, gear pumps, household appliances, fax machines, watches, toys, and other specialised products. If your application is not listed, contact our team with the torque, speed, operating temperature, and environmental conditions and we will advise on the appropriate material and module selection.

"We design multifunction office printers and use POM M0.7 spur gears from Korea Ever-Power in our paper-feed drive train — specifically the 24T + 52T Delrin 500P pair. Gear noise at our acoustic test bench is 3 dB lower than the previous metal gear equivalent. We ordered machined samples to validate bore fit before ordering the injection mould, which saved significant rework cost."

Kim Hyeon-woo  |  Mechanical Design Engineer, Incheon Office Equipment Co.  ·  Q1 2026

"We manufacture infusion pump drives and specified POM spur gears at M0.5. Korea Ever-Power provided machined samples within one week. Bore dimensions were stable through 50 autoclave sterilisation cycles at 121°C in a stainless steel housing — no measurable change. Production gears ordered after sample confirmation."

Lee Su-bin  |  Pump Mechanism Engineer, Seoul Medical Devices Co.  ·  Q4 2025

"We supply stepping motor positioning stages and use POM M1.0 spur gears for the reduction stage. Korea Ever-Power's gears run 18 months dry (no lubrication) in a sealed electronics enclosure with no measurable backlash increase at our annual measurement check. Low inertia allows us to use a 40% smaller motor than the equivalent metal gear stage."

Park Jae-min  |  Automation Drive Engineer, Gyeonggi Positioning Systems  ·  Q2 2026

"We make household kitchen appliances and import Nylon spur gears M1.5 from Korea Ever-Power for our blender reduction stage. The quiet operation and no-lubrication requirement suits our sealed plastic housing. We have Korea Ever-Power machine the bore to a tight tolerance so the gear is a light press fit on the motor shaft — no keyway needed at this torque level."

Choi Yeon-ji  |  Product Development Engineer, Busan Home Appliances Co.  ·  Q3 2025

"We source M0.3 POM spur gears for miniature watch display mechanisms. Korea Ever-Power machined these from Delrin 500P rod — no injection mould was required at our annual volume. Tooth accuracy confirmed under optical CMM. At M0.3, the tooth height is only 0.675 mm — the machined samples came within our ±0.01 mm tooth thickness tolerance on every piece."

Yoon Soo-hyeon  |  Miniature Mechanism Designer, Daejeon Precision Instruments  ·  Q1 2025