Gear Manufacturers Customize All Kinds of Plastic Gear

Korea Ever-Power's plastic injection factory provides professional custom plastic gear manufacturing covering all gear styles — spur gears, bevel gears, helical gears, double/duplicate gears, and pinion gears — in any engineering plastic material including Nylon (PA6/PA66/PA66+GF), POM, PEEK, PVC, PPS, ABS, UPE, PE, TPE, PP, PC, PET, PMMA, and PAI. Mould steel grades: S136H, NAK80, 718H, SKD61 hot-hard, H13 hot-hard, 420 hot-hard — selected by product size, required precision, and production volume. Diameter 5–200 mm or fully customised. Tolerance ±0.05 mm. Certification: ISO9001, SGS, Test Report, RoHS.

Korea Ever-Power's custom plastic gear service covers the complete process from customer inquiry to production: gear type and material consultation, drawing design from customer sample if no drawing available, mould tooling design and manufacturing, trial samples, and series production. All specific sizes, colours, quantities, and materials can be customised to customer requirements. 24-hour customer service; shipping status notification; regular new-style notifications.

Spur Gears

Helical Gears

ベベルギア

Double Gears

Step 1 — Application Analysis

Before designing the gear, Korea Ever-Power engineers define the application requirements: required torque and speed at the gear; duty cycle (continuous vs intermittent); ambient temperature range; chemical and moisture environment; required service life; available space envelope; shaft arrangement (parallel, 90°, or other); and required precision grade. These inputs determine the gear type, module, face width, material, and tooth form — errors at this stage propagate into expensive mould rework or short gear life.

Step 2 — Tooth Flank Design

Plastic gear tooth flanks are designed to minimise moulding stress while maximising load-carrying capacity. The tooth root radius is typically increased beyond the standard involute value to reduce the stress concentration at the root — where injection-moulded plastic gears most commonly fail by fatigue fracture under repeated loading. The tooth tip is designed for adequate clearance with the mating gear under all temperature and moisture conditions — dimensional change in plastic gears is larger than in metal, so adequate clearance at the cold/dry extreme prevents interference at the hot/wet equilibrium condition.

Step 3 — Module and Face Width Selection

Smaller modules (finer teeth) give smoother action and lower noise but reduce load capacity per unit face width. The minimum practical module for injection-moulded plastic gears is M0.1–M0.2 (for POM); below M0.5, tooth form accuracy becomes highly dependent on mould quality and shot-to-shot consistency. Face width is chosen to give adequate tooth contact area at the operating load, but slightly narrower than the equivalent steel gear — reducing the risk of mechanical interference at the toe end and stress concentration from tooth misalignment due to plastic shaft/housing deflection under load.

Step 4 — Mould Steel Selection

Korea Ever-Power selects mould steel by the gear's production volume and precision requirement: S136H (stainless, corrosion-resistant) for food-grade or medical gear moulds where the mould itself must resist cleaning chemicals; NAK80 (pre-hardened, good polishability) for standard high-precision optical-surface gear moulds; 718H (pre-hardened, good toughness) for large moulds where toughness is prioritised; SKD61/H13 hot-hard for high-volume, long-life moulds at maximum hardness; 420 hot-hard for maximum corrosion resistance at high hardness. The correct mould steel selection determines mould life in millions of shots.

Step 5 — Diameter Design Rule

Korea Ever-Power designs plastic gears with rim diameter greater than 1 × module × tooth count — ensuring adequate rim material behind the tooth root to support the tooth root bending moment and distribute the stress through the rim before it reaches the gear bore/hub. This is especially important for plastic gears where the lower elastic modulus means more deflection at the tooth under load — if the rim is too thin, the rim deflects under tooth load, changing the contact geometry and accelerating wear at the heel or toe end of the tooth.

Prototype Before Production

For new custom gear designs, Korea Ever-Power strongly recommends CNC-machined prototypes before mould commitment. A machined prototype in the specified material (POM, nylon, PEEK) tests the tooth form, fit, and function in the application before the significant tooling investment. If the prototype test identifies a required change (module, tooth count, bore diameter, face width), the change is made to the drawing and the corrected prototype is tested again — all at minimal cost compared with modifying a finished mould. Only after prototype approval does the mould tooling manufacturing begin.

Automotive — Fastest Growing Segment

Automakers integrate plastic gears into liftgates, power seats, electronic throttle bodies, turbo actuators, mirror adjusters, window lift drives, and HVAC blend door actuators. PA66+GF30 gears dominate automotive applications for their high strength and temperature resistance; POM gears suit lower-temperature interior applications. Korea Ever-Power holds TS16949 certification and manages the full mould-to-production supply chain for automotive OEM gear requirements.

Medical Equipment

PEEK and POM custom plastic gears in surgical robots, infusion pumps, diagnostic analysers, and rehabilitation equipment. Biocompatibility requirements (FDA-listed POM; PEEK for implant-adjacent contact), cleanroom manufacturing, full material traceability, and ISO9001 certification align with Korea Ever-Power's standard quality systems for medical device gear supply.

Semiconductor Equipment

PEEK and PPS custom plastic gears in semiconductor wafer handling robots, chemical vapour deposition chamber drives, and photolithography positioning mechanisms. Semiconductor equipment demands zero metallic particle contamination (metal gear wear is disqualifying), chemical resistance to aggressive process gases and cleaning chemicals (PEEK and PPS only), and ultra-high dimensional repeatability (DIN5–6 precision) for nanometre-level wafer positioning.

Food and Packaging Machinery

POM, UHMWPE, and food-grade PA custom gears in food processing, filling, and packaging machinery. FDA-listed materials, no-lubrication operation, corrosion resistance against acidic and alkaline cleaning agents (CIP), and easy visual inspection for wear damage (distinctive colour — natural POM is white, worn gear shows bare surface differently from new) are all characteristics of Korea Ever-Power food-grade gear designs.

Robotics and Automation

POM and nylon custom plastic gears in collaborative robots, educational robots, automated guided vehicles, and industrial positioning systems. The combination of low weight (for robot arm inertia minimisation), self-lubrication (sealed joint drives), corrosion resistance (outdoor AGV operation), and competitive cost at production volumes makes custom plastic gears the standard choice for the gear train stages in collaborative robot joints rated up to 50 Nm.

Toys and Consumer Products

ABS and nylon custom gears in RC vehicles, educational toys, smart home devices, and consumer appliances. The combination of low per-part cost (injection moulding economics), design freedom (complex hub features, snap-fits, and integrated features in one part), and safety compliance (no heavy metals, no sharp edges) at consumer price points makes Korea Ever-Power custom plastic gear moulding the standard approach for consumer product gear drives at annual volumes above ~10,000 units.

What is the first thing to consider when choosing a plastic gear material?

Strength — the material must be rigid enough to withstand the expected loads without exceeding its allowable tooth root bending stress. After strength, consider: temperature resistance (must exceed the maximum operating temperature with adequate margin); water absorption (low absorption materials like POM or PPS for humid environments); friction coefficient (self-lubricating grades for maintenance-free drives); and chemical resistance (PPS, PEEK, or PTFE for aggressive chemical environments). Korea Ever-Power engineers will confirm the best material choice after reviewing your application requirements, load data, and operating environment.

What is the minimum order quantity and lead time for custom plastic gears?

There is no enforced minimum order quantity — Korea Ever-Power accepts development samples (1–10 pcs from CNC machining, 5–50 pcs first mould shot) through to high-volume production orders. Mould tooling lead time: 25–35 days for standard complexity; 15 days for simple small moulds. Series production lead time after mould approval: 10–20 days depending on quantity and current factory loading. Contact Korea Ever-Power with your specification and required delivery schedule for a specific commitment.

Can prototype gears be tested before committing to mould tooling?

Yes — Korea Ever-Power CNC-machines prototype gears in the specified plastic material (POM, nylon, PEEK, etc.) before mould design begins. Machined prototypes allow functional testing — including torque, noise, fit, and life testing — before the mould investment is committed. This prototype-first approach is strongly recommended for new gear designs: changes to module, tooth count, or bore at the prototype stage cost far less than the equivalent mould modification after tooling is cut. Contact Korea Ever-Power with your gear drawing or application description to begin.

"We develop industrial automation equipment and needed custom POM spur and helical gears across 6 sizes (M0.5–M2.0). Korea Ever-Power handled material selection consultation, drew the full gear specifications from our rough sketches, designed and built 6 moulds simultaneously, and delivered approved samples within 28 days. All 6 gear sizes passed our dimensional and functional tests on first sample submission. No mould modifications needed — exceptional first-time quality. Tolerance check: all teeth within ±0.03 mm on OD and ±0.04 mm on tooth thickness."

Kim Hyun-jae  |  Automation Equipment Design Engineer, Incheon Precision Systems Co.  ·  Q2 2026

"We manufacture automotive seat adjustment mechanisms and source PA66+GF30 spur gear packs (M1.5, DIN7) from Korea Ever-Power under TS16949. Temperature cycle test −40°C to +100°C, 200 cycles: no dimensional change beyond specification. Batch-to-batch consistency: shot weight Cpk 1.67 over 6 production batches. Korea Ever-Power's video production inspection before each shipment gives us confidence without sending a resident inspector. Their 24-hour response to production queries has been genuinely important for our production planning."

Lee Ju-won  |  Automotive Mechanism Quality Engineer, Gyeonggi Automotive Seating Co.  ·  Q1 2026