Customized Worm Gear Set | OEM/ODM, Ratio 20:1–300:1, Full Material & Gear Type Coverage

Product Overview

Every standard gear catalog was built for the most common applications. Module M4, ratio 20:1, C45 steel, 60-tooth wheel with Ø25 mm bore — this specification covers a large fraction of general industrial drives. But product engineering rarely produces the most common application. An automotive electric power steering column needs 73:1 from a compact package in 42CrMo with a left-hand worm. A medical positioning table needs 48:1 in stainless steel with a DIN7-class tolerance and a keyway at 15° to a specific face datum. A defense turret traverse needs 120:1 with carburized 20CrMnTi worm and a ductile iron wheel with machined mounting bolt circle. None of these exist in any catalog. Korea Ever-Power Worm Gear Co., Ltd manufactures custom worm gear sets to any ratio, any material pairing, any bore configuration — from 3D CAD files, 2D drawings, or physical samples when drawings are not available. The NDA is signed before the first drawing is shared.

  

Why Worm Gears for High-Ratio Single-Stage Drives

The worm — a cylindrical gear resembling a threaded screw — paired with a worm wheel allows smaller gearboxes or planetary drives while retaining full torque or power transmission capacity. It is common for worm gear reductions to reach 20:1 and extend to 300:1 or more in a single stage that would require two or three stages of helical gearing to replicate. The geometry that makes this possible also produces the most distinctive operational feature: the worm can effortlessly drive the worm wheel, but the worm wheel cannot drive the worm back. When the gear attempts to rotate the worm, the shallow lead angle of the worm thread means that friction between the contact surfaces keeps the worm locked in position — self-locking is a natural consequence of the geometry, not an add-on feature.

OEM Worm Gear Set — Full Service Scope

GB Steel Grade Guide — Selecting the Right Alloy for Your Application

The GB steel grade list in the OEM services table is not interchangeable — each grade has a specific combination of hardenability, core toughness, and heat treatment response that makes it appropriate for certain worm gear applications and inappropriate for others. Selecting the wrong grade produces premature tooth fatigue, inadequate surface hardness, or excessive brittleness after heat treatment. The guide below covers the six most commonly specified grades for worm gears in industrial and automotive applications.

Heat Treatment Selection — Quenching vs Carburizing vs Nitriding for Worm Gears

Heat treatment method is often specified without understanding what each process actually achieves at the tooth surface. The four methods in the OEM services table produce different hardness distributions, case depths, and residual stress states — with direct consequences for wear resistance, impact tolerance, and gear accuracy after treatment.

Processing Methods — What Each Operation Contributes to Gear Accuracy

The processing list in the OEM services table is not a menu of equivalent alternatives — each operation plays a specific role in the production sequence, and the combination determines the achievable precision class. Understanding this helps buyers specify a realistic process for their target tolerance without over-specifying expensive operations for tolerances that simpler processes can achieve.

• →Gear blank turning — Sets the OD, bore, and face dimensions. Accuracy here determines how well the gear runs true on the mandrel during hobbing. A poorly turned blank with bore runout produces a hobbed gear with periodic tooth spacing error — this error cannot be corrected by subsequent grinding.
• →Gear hobbing — The primary tooth-cutting operation. Achieves DIN8–DIN9 accuracy as-cut in most materials. The hob geometry determines the tooth profile; the hob mounting accuracy on the hobbing machine determines the lead error. Well-maintained hobbing equipment and sharp hobs are essential for DIN7 or better directly from hobbing.
• →Gear shaving — A finishing operation performed before heat treatment. A hardened shaving cutter removes 0.01–0.05 mm from the tooth flanks while simultaneously applying slight crowning (tooth profile modification) to reduce edge loading under misalignment. Achieves DIN6–DIN7 accuracy but cannot be performed after heat hardening — the tooth surface is too hard for the cutter. For applications requiring DIN6–DIN7 with carburized teeth, shaving is performed before carburizing and grinding is required after.
• →Tooth grinding — The only process capable of consistently achieving DIN5–DIN6 on hardened tooth flanks. A profiled grinding wheel removes 0.05–0.15 mm from the hardened tooth surface, correcting the geometric distortion introduced by the heat treatment cycle. Tooth grinding is the most expensive tooth-finishing operation — it adds significant cost to the per-piece price and requires grinding cycle development for each new gear geometry. Specify only when DIN5–DIN6 is confirmed as a requirement.
• →Broaching — Applied to internal keyways, splines, or non-circular bore profiles after gear teeth are cut. Broaching produces keyways and splines in a single pass with high geometric consistency — tolerances of ±0.005 mm on keyway width are achievable. For custom worm gear wheel bores with non-standard keyway positions or profiles, broaching is the correct process; milled keyways are appropriate where tight positional accuracy is not critical.

Custom OEM vs Standard Catalog — The Complete Procurement Comparison

The right sourcing strategy depends on the application, the production volume, and the supply chain risk tolerance. This comparison is written for engineers and procurement managers making a sourcing decision, not for marketing purposes — both options have legitimate use cases.

OEM Development Process — From First Contact to Validated Production

Custom gear development follows a defined sequence that protects both the buyer's IP and the supplier's production investment. Korea Ever-Power's standard process for new OEM worm gear set development:

• →Step 1 — NDA and inquiry. Before any drawing or sample is shared, an NDA is signed if requested. Inquiry is submitted with available information: target ratio, output torque (Nm), input speed (RPM), material preferences, operating environment, bore configuration, and quantity forecast. Missing parameters are confirmed through a brief technical exchange — we return a confirmed specification for approval before quoting.
• →Step 2 — Quotation and drawing confirmation. We return a price and lead time quotation with a confirmed 2D drawing or 3D model for approval. For reverse-engineered parts (from sample, no drawing), we return the measured drawing within 3–5 working days for customer confirmation before production.
• →Step 3 — Sample production. On drawing approval, samples are produced and typically ready in 15–25 working days depending on module size, material, and heat treatment method. Sample cost is charged separately and credited in full on the first production order.
• →Step 4 — Customer validation. Customer installs samples in the actual mechanism and validates fit, mesh quality, noise, backlash, and endurance cycle performance. Any corrections to bore, tooth profile, or surface finish are incorporated in a second sample round — typically 5–8 working days for a correction batch.
• →Step 5 — Production and dedicated tooling. On sample approval, tooling (hobs, fixtures, inspection gauges) is dedicated to this part number and retained in-house for the customer's production lifetime. Reorders are filled from the same setup — no re-qualification required. Production quantities ship with dimensional inspection records on request.

Application Sectors — Engineering Requirements Per Industry

• ▶Automotive (EPS, seat adjustment, sunroof, mirror, parking brake) — Automotive worm gear sets have the most demanding combination of requirements: compact packaging, high cycle count (10–30 million cycles over vehicle life), wide temperature range (−40°C to +125°C), specific torque envelope, and PPAP-compatible supply documentation. The worm is typically 20CrMnTi carburized and ground; the wheel is bronze or nylon depending on the noise requirement. Material traceability to mill certificate level is standard in Tier 1 supply chains.
• ▶Agricultural machinery (rotary tiller, transplanting, irrigation) — Agricultural drives experience the widest mechanical abuse of any gear application: shock loads from stone impacts, seasonal storage without lubrication for months, wide temperature swings, and field-level maintenance without special tools. 40Cr quenched-and-tempered worm shafts with aluminum-iron bronze wheels are the standard combination — higher core toughness than C45 for shock tolerance, higher strength than tin bronze for impact loads. Sealed gearbox housing retention of lubricant over months of storage is critical — specify IP67-rated sealing if the gearbox will be stored outdoors between seasons.
• ▶Electronic and semiconductor equipment — Wafer handling robots, probe station positioners, and semiconductor process chamber valves require extremely clean operation — no lubricant migration, no metal particle generation, and minimal vibration at the mesh frequency. Worm gears in these applications are typically M1.0–M2.0 in stainless steel or nitrided alloy steel, run dry or with PTFE grease, and held to DIN6–DIN7 for low backlash. The gear housing often requires special sealing to prevent particle contamination of the semiconductor process environment.
• ▶Medical equipment (surgical robots, positioning tables, infusion pumps) — Medical worm drives have unique requirements not seen in industrial applications: sterilization compatibility (autoclave 134°C or EtO gas), FDA-compliant or biocompatible surface treatments, traceable material certificates, and zero contamination tolerance. Stainless steel SS316 is the default material; lubrication is typically food-grade silicone or PTFE. Design review documentation and material certificates meeting ISO 13485 traceability requirements are provided on request.
• ▶Defense and off-highway (turret drives, tracked vehicle final drives, construction equipment) — Defense and off-highway worm gear sets are specified for maximum load capacity and maximum service life in extreme environments. 17CrNiMo6 or 20CrMnTi carburized worm shafts with DIN6-class tooth accuracy are common. Documentation requirements include full material traceability, proof load testing records, and in some cases first article inspection (FAI) reports to MIL or AQAP standards. Korea Ever-Power has produced defense-program gear sets and can support documentation requirements for military procurement.
• ▶Industrial automation (conveyors, packaging, solar trackers, hoists) — Industrial OEM drives span the widest range of requirements: from slow-speed high-load conveyor drives (40:1 to 100:1, bronze wheel, continuous 24-hour duty) to precision packaging machine feeds (15:1, DIN7, frequent start-stop) to solar tracker azimuth drives (60:1 to 150:1, sealed housing, 25-year service life). The key advantage of custom OEM for industrial automation builders is supply chain continuity — a standard catalog part may be discontinued when the catalog supplier changes; a custom part with dedicated tooling held by Korea Ever-Power is available as long as the product is in service.

Why Korea Ever-Power for OEM Worm Gear Sets

• ◈Full gear family coverage: spur, helical, bevel, hypoid, worm, and spline — one engineering team covers all gear types needed in a complex multi-stage drive, eliminating coordination between multiple specialized suppliers.
• ◈Diverse material supply in-house: all GB steel grades, copper alloys, engineering plastics — the matched worm and wheel come from the same quality system and material traceability record.
• ◈Reverse engineering capability: engineers can design from 3D CAD, 2D drawings, or physical sample parts when drawings are unavailable — CMM measurement returns a confirmed drawing within 3–5 working days.
• ◈Dedicated tooling retention: hobs, fixtures, and inspection gauges for customer parts are kept in-house for the production lifetime — reorders fill at standard lead time without setup charges.
• ◈No MOQ pressure for development: prototypes and small pre-production batches are accepted to support the validation process — production commitment is made after, not before, quality is confirmed.

Production Facility

Related Components

Worm Shaft — The hardened steel drive counterpart to the worm gear set . They can ensure a low-friction mesh, protects the worm shaft from accelerated wear, and supports quiet, reliable operation across a wide speed range.

Worm Gear Reducer — A fully enclosed unit integrating the worm and wheel within a sealed housing. Ideal when consistent center distances, simplified mounting, and protected internal components are required — particularly in humid or wash-down environments.

Packaging & Shipping

All gears are packaged for safe shipping and convenient storage, using the most appropriate materials and method for the gear type. Precision gear sets are individually wrapped in anti-rust VCI paper and sealed in polyethylene bags before boxing — this prevents surface oxidation during sea freight transit through humid environments. Large worm wheels are individually foam-mounted to prevent tooth face contact during transport. Wooden crates are used for shipments exceeding 50 kg or for gears with tight tolerances where carton handling may risk transit distortion.

We work with your freight forwarder to ship directly to your facility. If you do not have a forwarder, we arrange international shipment to any convenient port and work with experienced freight forwarders who regularly handle precision mechanical components to worldwide destinations.

Frequently Asked Questions

Can you produce customized products from our design drawings?

Yes. Korea Ever-Power is a professional metal fabrication and gear manufacturing supplier with an engineering team experienced in custom gear development. We accept 2D drawings in DWG, DXF, or PDF format, and 3D models in STEP, IGES, SolidWorks, or CATIA format. If your drawing is incomplete — for example, if the tooth profile tolerance or bore fit class is not specified — we will flag the gaps and return a confirmed specification for approval before production begins. We do not proceed with missing specifications that would affect the final function of the gear.

Will my drawing be secure?

Yes. We will not release your design, 3D model, or sample part information to any third party without your written permission. We sign NDA agreements before any drawing or sample is submitted — this is our standard practice for all new OEM customers, not an exception requested on a case-by-case basis. Production tooling made to customer specifications is treated as customer property held in our facility — it is not used for any other customer's production and is returned or destroyed on written request from the customer.

What is the minimum order quantity?

We do not set a rigid minimum order quantity. For standard-module custom worm gear sets (module M2–M8 in common steel grades), small quantities of 10–50 pieces are accepted for initial production validation. For non-standard modules or unusual material combinations requiring special tooling purchase, a minimum quantity corresponding to a reasonable amortization of tooling cost is discussed at quotation — typically 50–200 pieces for the first order, with no minimum on reorders once tooling is in-house. Contact us with your forecast and timeline and we will advise on the economically appropriate quantity structure.

Can samples be provided before a mass production commitment?

Yes. Samples are produced from the confirmed drawing before the production order is placed. Sample quantities are typically 3–10 pieces depending on the validation test protocol. Sample cost covers material, machining, and heat treatment and is charged separately from the production quotation. On placement of the production order, the sample cost is credited in full against the first production invoice. Sample lead time is 15–25 working days depending on module size, material, and heat treatment method.

How are non-conforming parts handled after delivery?

All our products pass QC inspection with an inspection report before delivery. Non-conformances are rare because the inspection step catches deviations before shipment. In the event that a non-conformance is found on receipt: contact us immediately with photographs and the specific dimensions or characteristics that fail your incoming inspection. We will review and respond within 24 hours on working days. Confirmed manufacturing defects are corrected by rework or replacement at our cost, including outbound freight for the replacement shipment. We do not dispute measurement data from calibrated instruments.

What are the payment terms?

Payment before shipment is required. Accepted payment methods are T/T (bank transfer) and L/C (letter of credit). For established customers with a purchase history, extended payment terms may be discussed — contact us. For first orders, the standard process is 30–50% deposit on order confirmation and 50–70% balance before shipment.

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