Plain Bore Yoke F-Vertical Pin Hole

Plain Bore Flexibility

The unmachined bore allows your workshop to finish the internal diameter to match your specific PTO shaft — from 20 mm up to 45 mm depending on the series. This eliminates the risk of ordering the wrong bore size and is particularly valued by UK machinery dealers who service multiple tractor brands.

Positive Axial Lock

The vertical F-series pin hole provides a robust mechanical connection between shaft and yoke. Under the harsh vibration and shock-loading typical of UK field conditions — stone-strewn soil, uneven terrain, sudden engage/disengage events — this locking method significantly reduces the risk of yoke loosening or slippage during operation.

Wide Series Coverage

With eight series (1.05 through 8.05) spanning outer body diameters from 22 mm up to 35 mm and yoke lengths from 54 mm to 106.5 mm, there is a configuration to suit light-duty garden machinery all the way through to heavy implement drive lines on 150 hp+ tractors commonly used across Yorkshire and Lincolnshire arable farms.

High-Grade Steel Construction

Each yoke is drop-forged from medium-carbon alloy steel and then heat-treated to achieve the strength and toughness needed for sustained high-torque service. Surface treatment with protective coating ensures corrosion resistance across the wet and muddy conditions that are a regular reality for machinery used in the British countryside throughout autumn and winter months.

Precision Machined Interfaces

The cross-journal bearing cap holes and yoke ear geometry are CNC machined to tight tolerances, guaranteeing proper cross-kit fit, balanced rotation, and minimised vibration at rated speed. This level of dimensional consistency is crucial when a yoke is being paired with a cross journal kit intended for 1,000 rpm or 540 rpm PTO output — the two standard speeds used on UK tractors.

OEM & Aftermarket Supply

Whether you are an OEM manufacturer sourcing plain bore yokes for a new implement production run or a UK agricultural parts distributor replenishing aftermarket stock for the spring season, we supply at both small batch and high-volume quantities. Our order processing supports mixed-series orders, enabling distributors to consolidate procurement across multiple yoke configurations in a single shipment.

Material & Finish

The yoke body is manufactured from medium-carbon alloy steel (typically 35CrMo or equivalent), selected for its superior strength-to-weight ratio and its proven ability to withstand the cyclic fatigue loading inherent in rotating PTO driveline components. After forging, the blank undergoes quenching and tempering to reach a hardness range calibrated for both toughness and wear resistance. The bearing cap bore surfaces are precision ground, and the external surfaces receive a zinc-phosphate or electrophoretic paint finish that provides meaningful corrosion resistance against the damp, chemically active environments found in farm buildings, spreading operations, and outdoor storage — all common in the UK agricultural sector. Critical dimensions including the pin hole diameter (F), bore diameter (E), and cross-journal seat diameter (A) are held to ISO H7/f6 tolerance classes to ensure reliable assembly without field-fitting issues.

How It Works

The plain bore yoke functions as one half of a universal joint (U-joint) assembly. The yoke ears straddle the cross-journal kit, with needle-bearing cap assemblies seated in the machined bore holes of each ear. Torque from the tractor PTO stub shaft enters through the plain bore and is transmitted via the cross journal to the paired yoke on the other end of the shaft. The vertical pin hole (F dimension) is drilled precisely through the yoke hub perpendicular to the shaft axis. Once the plain bore has been finish-machined to your shaft diameter, a matching hole is drilled through the shaft, and a hardened roll pin or clevis pin is driven through both components, creating a positive mechanical interlock. This arrangement prevents rotational slippage and eliminates the risk of the yoke walking along the shaft during operation — a failure mode that can cause catastrophic implement disconnection at speed. The entire system is designed to accommodate the angular misalignment (up to approximately 15°–25° depending on series) generated as an implement follows ground contour independently of the tractor.

Arable & Mixed Farming

Rotary tillers, power harrows, seed drills, and ploughs throughout East Anglia and the East Midlands. The F-vertical pin retention provides confidence during deep cultivation at high tractor RPM.

Grassland & Livestock

Slurry tankers, muck spreaders, mowers, rakes, and balers operating across Welsh hillside farms and Scottish dairy operations. Resistance to moisture and chemical contamination is a primary concern here.

Construction Equipment

Compact utility loaders, trenchers, and soil compactors used on smaller UK construction sites. The plain bore yoke’s versatility allows rapid field assembly without dedicated tooling.

Industrial Drive Systems

Conveyor drives, industrial mixers, pump drives, and processing equipment in food manufacturing or aggregate processing plants throughout the North of England and the Midlands.

OEM Implement Manufacture

UK-based implement manufacturers sourcing plain bore yokes for new production runs benefit from the unmachined bore, which allows them to machine to their own design tolerances in-house without relying on pre-finished variants.

PTO Drive Shaft G Series

General-purpose series suitable for light to medium-duty implements. A popular choice for UK farms running compact tractors and versatile three-point linkage equipment.

PTO Drive Shaft S Series

Heavy-duty series engineered for high-torque applications. Well suited to bale wrappers, large rotary mowers, and forage harvesters operating in demanding British grassland conditions.

PTO Drive Shaft L Series

Long-reach series designed for applications where extended driveline length is required. Commonly used on wide-span machinery and custom fabrication projects across UK OEM workshops.

PTO Drive Shaft T Series

Telescopic series with adjustable collapsed and extended lengths. The ideal solution for implements with variable hitch geometry or machines that require frequent attachment and detachment in the field.

Need a non-standard bore size, a bespoke pin hole position, or a custom surface finish for a coastal or chemical-process environment? Our engineering team is ready to discuss your requirements and provide a competitive quote for both prototype and production volumes.

★★★★★

“We’ve been sourcing plain bore yokes for our mower and spreader assembly lines for three seasons now. The dimensional consistency is excellent — we bore them to our own tolerance in-house and have had zero rejection issues. Lead times from order to delivery at our Cambridgeshire warehouse have been reliable throughout.”

James H., Procurement Manager

Agricultural Machinery Manufacturer · East of England

★★★★★

“We run a fleet of contractors’ mowers and slurry tankers across farms in the Scottish Borders. Being able to get plain bore yokes in Series 5.05 and 6.05 with next-batch availability has saved us on more than one occasion during peak spreading season. The vertical pin hole design hasn’t given us a single issue in field use — which is more than I can say for push-fit yokes we tried previously.”

Angus M., Workshop Supervisor

Agricultural Contracting · Scottish Borders

★★★★★

“As an industrial drive systems integrator in the West Midlands, we needed PTO yoke components that could be sourced reliably in moderate volumes for pump drive assemblies. The Series 7.05 and 8.05 plain bore yokes covered our bore range perfectly. Technical support from the sales team was helpful in confirming cross journal compatibility before we committed to our first order.”

Rachel T., Engineering Director

Industrial Drive Systems Integrator · West Midlands