Internal Gears for Tractors and Cranes – Mild Steel, MOQ10

Korea Ever-Power's internal gears for tractors and cranes are premium-quality mild steel ring gears engineered for the two most demanding heavy-duty applications of internal ring gears: agricultural tractor final drives and crane hoisting planetary gearboxes. Both applications share the same fundamental requirement — a ring gear that can carry very high torque reliably over a long service life with infrequent maintenance access. Tractors work in dusty, wet, and vibrating field environments; cranes cycle repeatedly at rated load capacity. In both cases, the ring gear's tooth hardness, material integrity, and dimensional accuracy are the primary determinants of the drive's safe working life.

Korea Ever-Power is a factory — not a trading company — manufacturing internal gears for tractors and cranes with sincerity and hard work since 2007. MOQ 10 pieces. On-time delivery; production capacity available at any time. Box packing. Samples available. Quotation requires drawing (IGS, DWG, STEP, PDF) — design assistance provided if no drawing is available.

Full Output Torque Load

The ring gear in the tractor hub planetary carries the full wheel torque reaction — the torque that is trying to rotate the ring gear against the axle housing flange. At 5:1 final drive ratio, a 500 Nm axle shaft torque produces 2,500 Nm of reaction torque at the ring gear flange. This is the highest torque point in the entire tractor drivetrain, which is why the ring gear's tooth surface hardness, material grade, and flange bolt pattern are all critical to the hub's safe working life.

Shock Load Resistance

Agricultural field operation subjects the tractor hub ring gear to shock loads every time the wheel hits a rock, rut, or soil discontinuity. These shock events produce instantaneous torque spikes several times the rated torque — the ring gear's tooth core toughness (resistance to tooth fracture under impact) is the critical property for this duty. Korea Ever-Power's heat treatment process controls not just the tooth surface hardness but also the core hardness and toughness, to withstand the field shock loading that agricultural ring gears must survive.

Wet Environment Sealing

The tractor hub runs in oil — the hub ring gear is submerged in gear oil within the sealed hub housing. The ring gear's surface condition inside the oil environment determines the oil's contamination rate: a poorly finished ring gear sheds metallic particles into the oil, accelerating bearing and planet gear wear. Korea Ever-Power's finished ring gears have controlled surface roughness on the bore and tooth flanks, minimising particle generation in the hub oil throughout the service interval.

Rated Load Every Cycle

Unlike a tractor where the maximum torque is reached occasionally under heavy draught, a crane's ring gear may experience near-rated load on every single lift cycle. Over a 20-year service life at 50 lifts per day, a crane hoist ring gear may accumulate 350,000 full-load cycles — a very high cycle count that demands the maximum achievable tooth fatigue life from the ring gear material and surface treatment specification.

Safety-Critical Classification

Crane hoisting gearboxes are safety-critical components under FEM (European Materials Handling Federation) and ISO 4301 crane classification standards. The ring gear is the most structurally loaded element in the hoist — any ring gear tooth fracture during a loaded lift results in dropped load, which is a life safety event. This safety-critical classification drives the material, heat treatment, and inspection requirements for crane planetary ring gears that Korea Ever-Power's quality process addresses.

Dimensional Accuracy for Tight Housing Fit

Crane planetary ring gears are typically interference-fitted or close-clearance fitted into the gearbox housing bore. The ring gear's OD tolerance, roundness, and cylindricity must be controlled tightly to ensure the housing bore retains the ring gear against the full reaction torque without slipping. Korea Ever-Power's CNC turning of the ring gear OD and face to close tolerance is confirmed by CMM measurement before the gear is accepted for gear tooth cutting.

We Are a Factory

Korea Ever-Power is a factory — all production steps for tractor and crane internal ring gears are handled in one location. CNC gear shaping, CNC turning of OD and bore, heat treatment, and quality inspection are all in-house. No sub-contracting means no quality handoff risk and no communication delays between production steps. The factory's equipment — 30 sets CNC, 15 sets CNC turning, 10 sets sheet metal fabrication — provides the capacity for both prototype samples and production batches at any time.

On-Time Delivery

Korea Ever-Power guarantees on-time delivery for tractor and crane internal gears. The computerised production management system logs every step from order receipt through shipment — delivery date commitments are tracked against actual production progress. Customers can follow every step in real time. If a delay risk is identified during production, Korea Ever-Power notifies the customer immediately — not at the scheduled delivery date when it is too late to act.

Production Capacity Available Any Time

Korea Ever-Power's production capacity is available at any time for tractor and crane ring gear orders. There is no minimum booking lead time for the production facility. Orders placed today are scheduled immediately — the 14–30 day delivery window reflects the actual machining, heat treatment, and quality inspection time, not a queue wait. This production flexibility is important for agricultural customers who need gears for seasonal field maintenance windows.

CNC Machining Since 2007

Korea Ever-Power has focused on CNC machining since 2007 — 18+ years of accumulated experience in precision internal gear production. This experience covers the specific challenges of large-diameter internal gear shaping (chip clearance, cutter deflection, fixturing for uniform tooth depth), heat treatment of large ring gear blanks (distortion control, case depth uniformity), and post-heat-treatment correction of ring gear bore distortion — all critical for tractor hub and crane hoist ring gears.

Tractor Wheel Hub Final Drive

Internal ring gears for the planetary final drive in tractor rear axle hub assemblies. Mild steel with induction hardening — standard for compact utility to large row-crop tractors. Customisable bolt-flange configuration, bore diameter, and face width per tractor make and model. MOQ 10 suits parts distributor stocking requirements.

Crane Hoist Planetary Gearbox

Internal ring gears for multi-stage planetary hoist gearboxes on overhead travelling cranes, jib cranes, and port cranes. OD tolerance controlled for interference or close-clearance fit in the gearbox housing. Full material certificate and dimensional inspection report available for crane safety file documentation.

Winch and Windlass Drives

Internal ring gears for marine winch planetary gearboxes and anchor windlass planetary stages. The customisable material option (mild steel standard; alloy steel or stainless for marine environments) suits the range of corrosion requirements from inland crane gearboxes to offshore vessel winch drives.

Agricultural Machinery

Internal ring gears for combine harvester planetary main drives, self-propelled sprayer wheel motor planetary stages, and baler drive planetary gearboxes. Agricultural machinery shares the tractor's demanding duty profile — high shock loads, seasonal use, and field maintenance — requiring the same premium internal ring gear specification.

Industrial Lifting Equipment

Internal ring gears for industrial hoist planetary gearboxes in workshop hoists, construction material lifts, and maintenance platform drives. The tractor/crane specification covers a range of lifting applications where the ring gear duty is similar to the crane hoist — repeated lifting cycles at significant load fractions.

OEM and Aftermarket Replacement

OEM production and aftermarket replacement internal ring gears for major tractor and crane gearbox brands. Korea Ever-Power produces from the customer's drawing with the customer's part number marking. Delivery time 14–30 days from drawing confirmation; MOQ 10 pieces suits both OEM programme minimums and distributor aftermarket stocking levels.

How do I get a quotation for a tractor or crane internal ring gear?

Send the drawing in IGS, DWG, STEP, or PDF format, together with a detailed PDF if available. Specify the material requirement, surface treatment, accuracy grade, and quantity. Korea Ever-Power will provide professional advice on material selection and heat treatment specification for the specific tractor or crane application if required. If no drawing is available, Korea Ever-Power will send a sample drawing for reference or design the ring gear from the application requirements — OD, bore, module, tooth count, face width, and mounting interface.

What is the delivery time and how is it guaranteed?

Standard delivery time is 14–30 days from drawing confirmation and order placement. On-time delivery is guaranteed — Korea Ever-Power's computerised production system logs every step and tracks delivery date commitments. If a delay risk is identified during production, the customer is notified immediately so they can adjust their maintenance or construction schedule. For urgent requirements (pre-harvest tractor maintenance, crane inspection deadline), contact Korea Ever-Power with the required date and we will confirm if an accelerated schedule is possible.

What payment terms apply to tractor and crane ring gear orders?

Standard payment terms are 50% T/T in advance and the balance (50%) before shipment. The advance payment covers material procurement; the balance is due after production is confirmed complete and the goods pass final inspection. For established regular customers with a track record of orders, extended payment terms may be available — contact Korea Ever-Power to discuss. Wire transfer is the standard method; other arrangements can be discussed on enquiry.

What shipping method is used for tractor and crane ring gears?

For small quantities (MOQ 10 pieces, which typically weighs under 50 kg), Korea Ever-Power uses TNT, FedEx, or UPS express courier — fast, trackable, and the most practical for small to medium batches. For large quantities where the weight exceeds the economical limit for express freight, air cargo or sea freight is available and will be quoted at the order stage. Korea Ever-Power packs tractor and crane ring gears in export-standard boxes with appropriate cushioning for the gear's weight and surface quality protection. Contact our team for a freight quote to your destination.

"We are a tractor parts distributor and stock Korea Ever-Power's internal ring gears for tractor hub final drives. MOQ 10 matches our minimum stocking order perfectly. Delivery within 18 days across three reorder cycles — consistently within the 14–30 day window. The computerised production tracking means we can give our workshop customers a reliable parts ETA, which we couldn't do with our previous supplier."

Kim Bong-cheol  |  Agricultural Parts Distribution Manager, Incheon Farm Equipment Parts Co.  ·  Q1 2026

"We rebuild crane hoisting gearboxes and source internal ring gears for cranes from Korea Ever-Power. The OD tolerance on the ring gear confirmed on our incoming CMM measurement — within the H7 fit tolerance for interference fit in our gearbox housing. Material certificate included with delivery for our crane safety file. FedEx delivery to Busan in 3 days from shipment notice."

Lee Hyung-jun  |  Crane Gearbox Overhaul Engineer, Gyeonggi Crane Service Co.  ·  Q4 2025

"We supply tractor hub assemblies to OEM assembly lines. No drawing for our hub ring gear — Korea Ever-Power provided a reference sample drawing for approval, incorporated our modifications, and produced the first batch in 22 days from drawing sign-off. 50% advance payment process was smooth. All ring gears passed our incoming gauge check and hub assembly fit verification."

Park Dong-cheol  |  Tractor Hub Assembly Engineer, Busan Agricultural Equipment Co.  ·  Q2 2026

"We import tractor and crane ring gears for distribution in Australia. Sea freight from Hangzhou to Melbourne: 22 days. Korea Ever-Power's production capacity 'available at any time' claim proved accurate — we placed an urgent pre-harvest order outside our normal schedule and Korea Ever-Power accommodated it within the standard 14–30 day window. No delay, no premium charge."

Choi Hyeon-woo  |  Heavy Equipment Parts Import Manager, Daejeon Pacific Supply Co.  ·  Q3 2025

"We needed internal ring gears for a new 20-tonne crane hoist design — no existing drawing. Korea Ever-Power's design team proposed the module, tooth count combination, and material specification from our torque and speed requirements, produced the drawing, and confirmed the interference condition check. Sample in 20 days. Hoist gearbox passed rated load test without issue. Production order placed."

Yoon Cheol-soo  |  Crane Design Engineer, Ulsan Industrial Crane Systems Co.  ·  Q1 2025