KTR H/HD Series Precision Universal Joint Coupling – Needle Bearing Type, DIN 808, 4000 RPM

Factory direct | Needle bearing | 4000 RPM max speed | 45° angle per joint | DIN 808 | H7 bore | Keyway, square bore, hexagon bore options | Maintenance-free | Direct KTR H/HD replacement | OEM custom

The Apexcoupling H/HD series is a high-precision universal joint coupling manufactured to DIN 808 standards, designed as a direct replacement for KTR H and HD series couplings. Featuring needle roller bearings with permanent lubrication, this coupling delivers smooth, maintenance-free operation at speeds up to 4000 RPM with 45° articulation per joint. Available in single joint (H type) and double joint (HD type) configurations, the series features H7 finished bores with optional keyway, square bore, or hexagon bore – providing maximum flexibility for your application. With case-hardened joint bearing surfaces and pins, this coupling offers exceptional durability, precision, and long service life. The ideal solution for packaging machinery, woodworking equipment, multi-spindle drills, metallurgy, CNC machines, and general automation requiring reliable, high-speed power transmission.

✅ Direct KTR H/HD replacement – same dimensions, same performance. Needle bearing – maintenance-free, 4000 RPM. 45° angle per joint. H7 bore with keyway, square, or hexagon bore options.

Key Technical Specifications

🔧 Custom bores, unequal bores, inch sizes, and special materials available on request. Contact us with your specifications.

H/HD Series – Model Range & Specifications

📐 Additional sizes and custom dimensions available upon request. Contact our engineering team for custom sizing.

H Type (Single) vs HD Type (Double) – Which One Do You Need?

Rule of thumb:

• Use H type (single) when shafts are on the same plane but angled.

• Use HD type (double) when shafts are both angled and offset – provides smoother motion with up to 90° total articulation.

Product Structure – Needle Bearing Design

1. Joint Center Piece – Precision-machined cross axis with case-hardened bearing surfaces.

2. Two Hub Bodies – Interlinked by straps, precision-machined with H7 finished bores.

3. Needle Roller Bearings – Permanent lubrication, maintenance-free, enabling 4000 RPM operation.

4. Strap Connection – Securely connects the hub bodies to the center piece.

💡 How it works: The H/HD precision universal joint consists of a joint center piece and two hub bodies connected by straps. The needle roller bearings in the joint heads provide low-friction operation with permanent lubrication – eliminating the need for maintenance. The case-hardened bearing surfaces and pins ensure exceptional wear resistance and long service life. The single joint (H) compensates for angular misalignment only, while the double joint (HD) compensates for both angular misalignment and parallel offset.

Needle Bearing vs Plain Bearing – Performance Comparison

✅ Needle bearing (H/HD) is the superior choice for high-speed applications – offering higher efficiency, maintenance-free operation, and speeds up to 4000 RPM.

Bore Options – Choose Your Connection Type

Product Features & Advantages

Applications

• Packaging Machinery – Conveyors, wrapping machines, carton sealers

• Woodworking Machinery – Multi-spindle drills, routers, saws

• Multi-Spindle Drills – Precision drilling operations

• Metallurgical Equipment – Rolling mills, continuous casting lines

• CNC Machines – Feed drives, positioning systems

• Printing Equipment – Register control, high-speed operation

• Textile Machinery – Spinning, weaving equipment

• FA Automation – Pick-and-place systems, indexing tables

• General Industrial Machinery – Pumps, mixers, conveyors

Why Choose Apex Coupling for H/HD Universal Joints?

FAQ

Q: What is the difference between H type and HD type?
A: H type is a single universal joint – for angular misalignment only. HD type is a double universal joint – allows both angular misalignment and parallel offset, providing smoother motion with up to 90° total articulation.

Q: Is this a direct replacement for KTR H/HD series?
A: Yes. The H/HD series is fully interchangeable with KTR H and HD series couplings – same dimensions, same performance, no design changes required.

Q: What is the maximum operating speed?
A: The maximum permissible speed is 4000 RPM. The needle bearings limit the maximum permissible speed to 4,000 rpm.

Q: What is the maximum operating angle?
A: Each joint can operate up to 45° maximum diffraction angle.

Q: What bearing type is used?
A: The H/HD series features needle roller bearings with permanent lubrication – maintenance-free operation.

Q: What is the bore tolerance?
A: Standard finished bore tolerance is H7.

Q: What bore options are available?
A: We offer round bore (H7), keyway (DIN 6885-1 JS9), square bore, and hexagon bore.

Q: What materials are used?
A: The coupling is manufactured from steel (35SMnPb10) with case-hardened joint bearing surfaces and pins.

Q: Does the coupling require lubrication?
A: No. The needle bearings have permanent lubrication and do not require servicing.

Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores, unequal bores, inch sizes, and special materials available on request.

Request a Quote

Send us your model (e.g., 1H, 3HD), bore size, bore type (round/keyway/square/hexagon), and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours.