Tractor Spur Gear – Steel, 17T, OEM 50-1701212A, MOQ 30

Tractor spur gears are among the most demanding gear applications in agricultural machinery — they transmit the engine's power through the tractor's main gearbox and PTO (power take-off) shaft system, where they must withstand heavy shock loads from field terrain, large torque reversals during implement engagement, continuous high-torque operation at low speeds during ground cultivation, and long service intervals under challenging dusty and wet field conditions. Korea Ever-Power's tractor spur gears are steel-machined transmission components engineered to meet these demands: 17 teeth, 90 mm diameter, OEM part number 50-1701212A, weight 0.87 kg. Each gear is 100% tested before shipment.

Korea Ever-Power can change the speed and torque, the direction of motion, and the form of activity transmitted through the tractor spur gear set. High transmission efficiency, accurate transmission ratio, and extensive power range — the three core requirements of agricultural tractor gearbox gears — are achieved through professional software design, qualified steel selection, and quality assurance at every production step. Custom tractor spur gears designed per customer specifications are available for any working condition.

Change Speed and Torque

The spur gear pair's primary function in the tractor gearbox is speed and torque conversion. A 17-tooth pinion meshing with a 51-tooth wheel produces a 3:1 step-down: if the pinion turns at 1,800 rpm, the wheel turns at 600 rpm and the torque at the wheel is three times the torque at the pinion (less transmission losses). This torque multiplication is what allows a tractor engine producing 100 Nm at the flywheel to deliver 300–1,000 Nm at the PTO or drawbar, depending on the gear ratio selected.

Change Direction of Motion

An external spur gear pair reverses the rotation direction of the output shaft relative to the input. The tractor's reverse gear is typically achieved by inserting an idler spur gear between the input and output shafts — the two external meshes produce two direction reversals, resulting in the output rotating in the same direction as the input, while the intermediate idler gear changes the sign of the transmission ratio. The 50-1701212A tractor spur gear can serve as the input, idler, or output gear in this arrangement depending on the specific gearbox design.

High Transmission Efficiency

A correctly lubricated and aligned spur gear pair achieves 98–99% power transmission efficiency per mesh — less than 1–2% of the input power is lost to sliding friction and rolling contact losses at the tooth surface. In a tractor gearbox with three or four gear stages in the power path, the cumulative efficiency remains above 94–96%, which is significantly better than chain drives (90–95%), belt drives (85–95%), or hydraulic torque converters (80–90%). This efficiency advantage directly reduces fuel consumption for the same output power delivered to the drive wheels or PTO.

Accurate Transmission Ratio

The spur gear pair's transmission ratio is exactly the ratio of tooth counts — a 17-tooth and 51-tooth pair is exactly 3.000:1, not approximately 3:1. This exact ratio is guaranteed by the involute tooth profile's fundamental property (the law of gearing), which ensures a constant velocity ratio regardless of minor centre distance variations from manufacturing tolerance or thermal expansion. In GPS-guided precision farming applications where the tractor's ground speed must be accurately known from the PTO or transmission shaft speed, the spur gear's exact transmission ratio is the basis of the speed calculation.

Change Form of Activity

The tractor gearbox converts continuous rotary motion from the engine into the specific combination of speed, torque, and shaft orientation required by the ground drive, PTO, and hydraulic pump systems. In its PTO application specifically, the tractor spur gear set changes the form of activity from vehicle propulsion (low speed, high torque at the rear wheels) to implement drive (540 rpm or 1,000 rpm at the PTO shaft for running mowers, balers, ploughs, and other driven implements). This versatility — one engine, multiple output forms — is the tractor's fundamental design principle, and the spur gear set is the mechanical element that enables it.

Extensive Power Range

Agricultural tractors range from 15 kW compact utility tractors to 350+ kW large row-crop tractors, all using spur gear-based main gearboxes. The spur gear's power range scales with module size, face width, and material hardness — Korea Ever-Power designs tractor spur gears to the specific power and torque requirement of each tractor platform, from the OEM replacement 50-1701212A through to custom designs for tractors across the full power spectrum.

Steel Inspection

Incoming steel billet: chemical composition by spectrometer, hardness by Rockwell tester. Reject brittle or off-grade steel before machining.

CNC Machining

CNC turning, boring, and gear hobbing. Dimensions checked at each CNC operation with calibrated gauges.

Heat Treatment

Induction hardening or carburising per steel grade. Temperature and time controlled. Hardness checked per furnace batch with test coupons.

100% Hardness Check

Every gear hardness-tested by portable Rockwell tester. Gears below minimum hardness are quarantined and re-treated or rejected.

Dimensional Inspection

Bore, OD, face width, and key dimensions checked per gear. Tooth profile and pitch inspected at statistically representative sample from each batch.

Visual & Packing

Visual inspection for surface cracks, nicks, or machining defects. Anti-rust treatment. Individual wrap. Carton packing with OEM part number marking.

Main Tractor Gearbox

50-1701212A tractor spur gears as direct OEM replacement or equivalent parts for main gearbox gear sets in compact to mid-range agricultural tractors (20–100 kW). The 17-tooth count and 90 mm diameter suit the intermediate shaft speed reduction stages where the gear ratio step-down from engine speed to slow field drive speeds is achieved.

PTO Drive Train

Tractor spur gears in the PTO speed selection gearbox — the stage that establishes either the 540 rpm or 1,000 rpm PTO speed from the engine. The 17-tooth gear at this position in the PTO drive train is the pinion of a speed reduction pair, where accurate transmission ratio is critical: a 540 rpm PTO that actually runs at 520 or 560 rpm will cause implement operation errors or damage on implements with speed-sensitive mechanisms.

Creeper and Field Speed Stages

Tractor spur gears in the slow-range (creeper) gearbox stages used for transplanting, precision seeding, and vineyard cultivation at below 2 km/h. These stages carry the highest torque in the tractor gearbox (maximum engine torque × total gear ratio above them) and require the highest-strength steel grades and surface hardness — Korea Ever-Power selects 42CrMo or 20CrMnTi carburised steel for these high-duty creeper stage tractor spur gears.

Tractor Gearbox Repair and Overhaul

OEM part number 50-1701212A replacement supply for agricultural equipment dealers, tractor maintenance workshops, and fleet repair operations. The MOQ 30 pieces suits dealer parts stocking levels. 100% testing before shipment eliminates the incoming inspection burden at the repair workshop for a safety-critical drivetrain component.

Agricultural Machinery Export

Export supply of tractor spur gears to agricultural equipment distributors and tractor parts wholesalers in Australia, Europe, South Korea, Brazil, and Southeast Asia. Carton packing with OEM part number marking facilitates re-export and on-shelf identification at distributor warehouses. Korea Ever-Power supplies standard OEM part numbers and custom-specified gear designs from the same facility.

Construction and Utility Equipment

Custom tractor-class spur gears for compact utility loaders, skid steer gearboxes, and small construction equipment drive trains that use similar gear sizes and materials to agricultural tractor gearboxes. Korea Ever-Power's custom design service extends the 50-1701212A production capability to these adjacent machinery sectors using the same steel grades, heat treatment processes, and quality testing protocol.

What does 100% tested mean for tractor spur gears?

100% tested means that every individual gear in the production batch is inspected before shipment — not a sample or a batch representative. For tractor gearbox components, where a single defective gear causes a gearbox failure during field operation (resulting in costly downtime and a complex field repair), 100% inspection is the correct quality level. Korea Ever-Power's 100% testing covers the critical parameters: bore diameter (fit to shaft), OD (assembly clearance in gearbox housing), face width (contact pattern and axle alignment), and surface hardness (gear life). Visual inspection for cracks or nicks completes the 100% test protocol before anti-rust treatment and carton packing.

Can Korea Ever-Power produce custom tractor spur gears for different tractor models?

Yes — Korea Ever-Power produces custom tractor spur gears per customer drawing or OEM part number for any tractor model. The OEM part number 50-1701212A (17 teeth, 90 mm diameter) is one specific example; Korea Ever-Power produces the full range of tractor gearbox spur gears from the smallest idler pinions to the largest output gear wheels across the power range. For custom tractor spur gear orders, provide the OEM part number, tractor make and model, or a dimensioned drawing. Korea Ever-Power will confirm the feasibility, steel grade, heat treatment, and lead time.

Why is the MOQ 30 pieces for tractor spur gears?

How does professional software improve tractor spur gear design?

Korea Ever-Power's design engineers use gear design software that calculates tooth root bending stress (per ISO 6336 Part 3) and contact (Hertzian) stress (per ISO 6336 Part 2) for the specific duty cycle of each tractor gear position. The software optimises the tooth proportions — addendum, dedendum, tip relief, root fillet radius — to minimise the peak stress at the tooth root under the application's loading spectrum. The result is a gear with better fatigue life, or a lighter gear with the same fatigue life, compared with a gear designed using simplified manual calculation methods. For tractor OEM applications where gear weight is a significant factor in the gearbox design budget, the software's optimisation capability produces a more competitive product.

What is the lead time for an OEM replacement order (50-1701212A)?

Lead time for a standard OEM replacement order at MOQ 30 pieces is confirmed at the quotation stage based on current production loading. For the 50-1701212A standard gear, machining, heat treatment, 100% testing, and carton packing are all in-house — the lead time depends on the material procurement status and CNC scheduling. Agricultural parts distributors with seasonal demand peaks (spring planting, harvest) should place forward orders during the off-season to avoid lead time pressure during peak tractor use periods. Contact Korea Ever-Power with the OEM part number and required quantity for a confirmed lead time and quotation.

"We are an agricultural equipment distributor and stock OEM tractor spur gear 50-1701212A from Korea Ever-Power for our dealer network. The 100% tested commitment is the reason we specified Korea Ever-Power over lower-cost alternatives — tractor gearbox failures during harvest are unacceptable to our dealer customers. MOQ 30 pieces matches our standard stocking unit. Hardness confirmed at our incoming check."

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

"We operate a tractor maintenance workshop and source Korea Ever-Power's tractor spur gears for gearbox overhauls. 100% tested before shipment means our mechanics can fit the gears directly without incoming dimensional checking — a significant time saving at field service workshop pace. We have fitted 47 of these gears across multiple overhauls with no dimension or hardness non-conformances."

Lee Gyeong-su  |  Tractor Gearbox Maintenance Manager, Gyeonggi Agricultural Equipment Workshop  ·  Q4 2025

"We manufacture compact utility loaders and needed custom spur gears — similar size and duty to the tractor 50-1701212A gear but with a different tooth count for our specific drive ratio. Korea Ever-Power produced the custom gear from our drawing using 42CrMo induction hardened to 54 HRC. 100% testing applied to our custom gear as to the standard OEM part. Lead time confirmed within the same window as the standard product."

Park Hyeon-cheol  |  Drive Train Engineer, Busan Construction Equipment Co.  ·  Q2 2026

"We export tractor parts to Brazil and Australia and source the 50-1701212A from Korea Ever-Power. The 0.87 kg gear packs efficiently at MOQ 30 in a standard carton — carton weight and dimensions confirmed with the first order and unchanged since, which simplifies our freight booking. Three-year supply relationship with no dimensional non-conformances and no hardness failures at our customers' incoming checks."

Choi Yeong-jun  |  Agricultural Parts Export Manager, Daejeon Farm Equipment Export Co.  ·  Q3 2025

"We manage a large fleet of agricultural tractors and use Korea Ever-Power's tractor spur gears for planned gearbox maintenance overhauls. The gears are ordered in seasonal batches (pre-spring planting, pre-harvest) to avoid field season supply delays. Steel grade and heat treatment confirmed on the material certificate. Fleet gearbox overhaul interval extended from 2,000 hours to 3,000 hours since switching to Korea Ever-Power's 100%-tested gears."

Yoon Tae-geun  |  Agricultural Fleet Maintenance Manager, Ulsan Cooperative Farm Management  ·  Q1 2025