Description
Plain Bore Yoke with C-Keyway & Threaded Hole
Engineered for demanding agricultural and industrial PTO drive shaft applications across the United Kingdom, this Plain Bore Yoke with C-Keyway and Threaded Hole delivers precision torque transmission, robust material quality, and exceptional dimensional consistency.
Why This Yoke Outperforms Standard Alternatives
Material Science Behind the Design
The Plain Bore Yoke C-Keyway and Threaded Hole component begins as a billet of medium-carbon alloy steel — typically a 40Cr or 42CrMo grade — which is rough-forged to shape before undergoing CNC turning and milling. This forging-first approach aligns the steel’s grain structure with the part’s load-bearing axis, producing measurably higher fatigue resistance compared to yokes cut from bar stock alone. After rough machining, parts proceed through normalising and quench-and-temper heat treatment, achieving a core hardness in the 28–34 HRC range, then receive a final precision bore grind so that the internal diameter meets H7 tolerance requirements consistently across production batches.
The C-keyway geometry is a deliberate engineering choice over a full keyway. By retaining the bottom arc of the bore, the C-cut preserves more material cross-section at the weakest point of a slotted bore, improving resistance to crack initiation under combined torsion and bending. The threaded radial hole — typically M6 to M14 depending on bore size — accepts a grub screw that bears directly on the key, preventing the key from walking axially during load reversal cycles. Together, these two features give assembly technicians a belt-and-braces locking strategy that is particularly valued in UK farming applications where PTO shafts on mowers, tedders, and silage machinery routinely experience rapid direction changes.
Surface protection is applied as an electroplated zinc finish or an epoxy-primer-coated layer depending on customer specification, providing corrosion resistance adequate for outdoor storage and field exposure typical of British conditions. Custom phosphating or hot-dip galvanising can be arranged for applications exposed to slurry or coastal salt environments.
Technical Specifications
All dimensions in millimetres. Custom bore diameters and keyway profiles available on request. Contact our technical team for non-standard specifications.
Where These Yokes Work Hardest
Complete PTO Drive Shaft Series
The Plain Bore Yoke C-Keyway and Threaded Hole is part of a broader family of precision PTO drive shaft components. Depending on your torque rating, operating angle, and attachment interface, one of the following series may be the right match for your application:
Our Manufacturing Capability & Custom Service
Ever-Power operates a vertically integrated manufacturing facility with in-house forging, heat treatment, CNC machining, and quality inspection capabilities. Our engineering team can accommodate non-standard bore diameters, alternative keyway profiles (B-type, parallel, involute spline), special grub screw thread specifications, and custom surface treatments — all achievable within standard lead times for orders placed from the UK and wider Europe.
For OEM customers requiring private-label components or machinery manufacturers wanting to streamline their supply chain, we offer dedicated part number assignment, custom packaging, and scheduled batch deliveries. Our production line routinely processes export documentation for UK importers, including CE declarations of conformity and material test certificates traceable to each production batch.
How UK and European Customers Use These Yokes
The following case represents a typical deployment scenario drawn from our technical support and sales records.
Lincolnshire Arable Contractor Eliminates Mid-Season Shaft Failures
A family-run agricultural contracting business based in Lincolnshire was experiencing repeated yoke bore failures on their fleet of six square balers operating across a combined area of approximately 2,400 hectares per season. The original equipment yokes were sourced from a European aftermarket supplier, but inconsistent bore tolerances meant field staff were spending up to 40 minutes per machine per week re-tightening loose grub screws — a significant drain on harvest throughput during peak August conditions.
After contacting Ever-Power with the OEM part references, our applications team specified a 4.05C30 yoke for the primary tractor-to-gearbox connection and a 5.05C35 for the baler’s secondary feed shaft. The C-keyway geometry and M8 grub screw arrangement provided the dual retention the original design lacked. The contractor reported zero bore failures across the following two harvest seasons, and the technical team noted a measurable reduction in vibration noise within the baler chassis — an indirect indicator of improved shaft alignment.
“We’ve been sourcing plain bore yokes from Ever-Power for three seasons now. The machining quality is noticeably better than what we were getting from our previous supplier, and the lead time from order to delivery into our Yorkshire depot has never exceeded twelve working days.”
“As a groundworks contractor based in the Midlands, our mixer drives take a real hammering. The 6.05C40 yokes from Ever-Power have held up perfectly for two full construction seasons on our compactor and mixer attachments. Absolutely no movement in the bore.”
“We maintain PTO drive shafts for a dairy operation in County Down and switched to Ever-Power yokes after a competitor’s parts caused a misalignment issue with our milking parlour conveyor. The dimensions matched the OEM drawing exactly. Great documentation support too.”
Frequently Asked Questions
Tell us your series, bore diameter, quantity, and delivery address. Our technical sales team responds to UK enquiries within one business day.
Get a Quote — [email protected]
edit by gzl
