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UNKA Universal Joint Coupling – CSKA / CSKW Precision Miniature Cross Needle Bearing Cardan Joint | Custom
Model Number
Check below, custom
| Type | Model | Outer Diameter (mm) | Length (mm) | Inner Diameter (mm) |
|---|---|---|---|---|
| Single | UNKA10 | 20 | 42 | 10 |
| Single | UNKA12 | 23 | 52 | 12 |
| Single | UNKA14 | 25 | 59 | 14 |
| Single | UNKA16 | 32 | 74 | 16 |
| Single | UNKA20 | 36 | 87 | 20 |
| Double | UNKW10 | 20 | 67.5 | 10 |
| Double | UNKW12 | 23 | 83 | 12 |
| Double | UNKW14 | 25 | 94.5 | 14 |
| Double | UNKW16 | 32 | 117.5 | 16 |
| Double | UNKW20 | 36 | 139 | 20 |
- Phone : +86 13431039760
- Wechat : +86 13431039760
- Whatsapp : +86 13431039760
- Email : ella@apexcoupling.com
Product Description
UNKA Universal Joint Coupling – CSKA / CSKW Precision Miniature Cross Needle Bearing Cardan Joint
Factory Direct | 42CrMo Alloy Steel | H7 Precision Bore | Needle Roller Bearings | Up to 40° Working Angle | Custom Bores & Surface Finishes
Product Overview
The UNKA Universal Joint Coupling is a precision-engineered flexible coupling designed for transmitting torque between shafts with angular misalignment. Also known as a cardan joint, cross joint, or universal joint coupling, this compact component is widely used in factory automation, servo/stepper motor systems, CNC machines, packaging equipment, and precision motion control applications.
Featuring needle roller bearings and fixed pins inside the yoke, the UNKA series delivers smooth rotation, low backlash, and high transmission efficiency in both clockwise and counterclockwise directions. The standard material is 42CrMo alloy steel – a high-strength alloy known for excellent toughness, fatigue resistance, and impact resistance after heat treatment. For special environments, 304 stainless steel is also available.
Available types include CSKA (single fixed keyway type), CSKW (double fixed keyway type), and CSCA (pin type). Optional CSC / CSW rubber sleeves are available for dust protection and extended service life.
📧 Get a Quote: ella@apexcoupling.com | WhatsApp/WeChat: +86 13431039760
Key Features
| Feature | Benefit |
|---|---|
| 42CrMo Alloy Steel | High strength and toughness; heat-treated for excellent fatigue resistance, impact resistance, and wear resistance |
| Needle Roller Bearings | Low friction, smooth rotation, low noise, and high efficiency |
| H7 Precision Bore | Tight tolerance ensures high concentricity, accurate shaft fit, and stable transmission |
| Large Angle Compensation | Recommended continuous working angle up to 30°; normal operation within 40°; limit angle 45° per joint |
| Low Inertia | Small transmission inertia allows fast response and flexible angle adjustment |
| Precise Fit & Low Backlash | Tight connection, flexible selection, and reliable operation in forward and reverse rotation |
| Multiple Fixing Options | CSKA single keyway, CSKW double keyway, CSCA pin type – choose according to your shaft design |
| Optional Surface Treatments | Default: natural polished + black oxide. Optional: nickel plating, zinc plating, mirror polishing |
| Optional 304 Stainless Steel | Available for corrosion-resistant applications |
| Optional Rubber Sleeve | CSC (single lining) / CSW (double lining) rubber sleeves for dust protection |
Technical Specifications
| Parameter | Details |
|---|---|
| Brand | apexcoupling |
| Model | UNKA |
| Order No. | UNKA |
| Product Code | CSKA / CSKW / CSCA |
| Standard No. | UNKA |
| Coupling Type | Universal Joint Coupling / Cardan Joint |
| Material | 42CrMo Alloy Steel (standard); 304 Stainless Steel (optional) |
| Bore Tolerance | H7 Precision |
| Bore Diameter | Custom (standard range 10–20 mm; other sizes available) |
| Rated Torque | Custom / model dependent |
| Allowable Torque | Custom / model dependent |
| Outer Diameter | Custom / model dependent |
| Length | Custom / model dependent |
| Weight | Custom / model dependent |
| Surface Finish | Natural polished + black oxide (default); nickel, zinc, mirror polish optional |
| Working Angle | 30° continuous; 40° normal; 45° limit per joint |
| Certification | ISO Certified |
| Place of Origin | Guangdong, China |
| Cross-border Export | Yes |
Standard Dimensions – CSKA / CSKW Series
| d (mm) | D (mm) | L – Single Joint (mm) | LD – Double Joint (mm) | A (mm) | L1 (mm) | C (mm) | E (mm) | b (mm) | t (mm) | M (Thread) |
|---|---|---|---|---|---|---|---|---|---|---|
| 10 | 20 | 42 | 67.5 | 25.5 | 21 | 12 | 6 | 3 | 1.4 | M5 |
| 12 | 23 | 52 | 83 | 31 | 26 | 15 | 7.5 | 4 | 1.8 | M5 |
| 14 | 25 | 59 | 94.5 | 35.5 | 29.5 | 17 | 8.5 | 5 | 2.3 | M6 |
| 16 | 32 | 74 | 117.5 | 43.5 | 37 | 22 | 11 | 5 | 2.3 | M6 |
| 20 | 36 | 87 | 139 | 52 | 43.5 | 25 | 12.5 | 6 | 2.8 | M6 |
Dimensions are for reference. Custom bores, keyways, splines, and lengths are available upon request.
Available Types
| Type | Description |
|---|---|
| CSKA | Single fixed keyway type – compact, ideal for simple angular misalignment |
| CSKW | Double fixed keyway type – higher torque capacity and stability |
| CSCA | Pin type universal joint – no keyway, fixed by pins |
| CSC / CSW Rubber Sleeve | Optional rubber boots: CSC single lining, CSW double lining |
Applications
The UNKA / CSKA / CSKW universal joint coupling is widely used in:
Factory Automation (FA) – Standard automation equipment, robotic arms, conveyors
Servo & Stepper Motor Systems – Precision motion control and positioning
CNC Machine Tools – Milling, drilling, tapping, and engraving machines
Packaging Machinery – High-speed packaging and filling lines
Semiconductor Equipment – Wafer handling and precision stages
Printing Machinery – Registration and tension control systems
Food Machinery – Hygienic and reliable drive connections
Woodworking Machinery – Routers, saws, and edge banding machines
Medical Equipment – Diagnostic and surgical positioning devices
Photovoltaic / Solar Equipment – Tracking and positioning systems
Why Choose Apexcoupling?
🏭 Factory Direct – Integrated manufacturing and trading, competitive pricing
🔩 Premium 42CrMo Alloy Steel – High strength, toughness, and wear resistance
⚙️ Needle Roller Bearings – Smooth, low-noise, high-efficiency operation
📐 H7 Precision Bore – High concentricity and accurate shaft fit
🛠️ Full Customization – Bores, keyways, splines, materials, and surface finishes
📦 Large Stock – Standard models ready for immediate shipment
💬 Expert Technical Support – We help you select the correct model for your application
Custom & Non-Standard Orders
We support complete customization for UNKA / CSKA / CSKW universal joint couplings:
Custom bore diameters and lengths
Single keyway, double keyway, pin type, and spline bores
42CrMo alloy steel or 304 stainless steel
Surface treatments: black oxide, nickel plating, zinc plating, mirror polishing
Optional CSC / CSW rubber sleeves
OEM/ODM with your branding
Drawing-based production
📧 Send your drawing or requirements to: ella@apexcoupling.com
Get a Quote Today
Ready to order or need more information? Contact us directly:
📧 Email: ella@apexcoupling.com
📱 WhatsApp / WeChat: +86 13431039760
🌐 Website: www.apexcoupling.com
We reply within 24 hours with pricing, availability, and technical recommendations.
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CSKA universal joint
