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UNKA/UNKW & CSKA/CSKW Precision Miniature Universal Joint Coupling – Keyway/Pin Type, 42CrMo / 304SS
Model Number
Check below, custom
- Phone : +86 13431039760
- Wechat : +86 13431039760
- Whatsapp : +86 13431039760
- Email : ella@apexcoupling.com
Product Description
UNKA/UNKW & CSKA/CSKW Precision Miniature Universal Joint Coupling – Keyway/Pin Type, 42CrMo / 304SS, 20.1 N·m
Factory direct | FA factory automation standard | 42CrMo alloy steel or 304 stainless steel | Single (UNKA/CSKA) or double (UNKW/CSKW) | Keyway or pin fixation | 45° angle per joint | 20.1 N·m torque | H7 bore | Large stock | OEM/ODM/OBM
The Apexcoupling UNKA/UNKW and CSKA/CSKW series are precision miniature universal joint couplings manufactured to FA factory automation standards. Available in single joint (UNKA/CSKA) and double joint (UNKW/CSKW) configurations, these couplings are designed for reliable power transmission in packaging machinery, woodworking equipment, multi-spindle drills, metallurgical machinery, and general automation applications. Constructed from 42CrMo alloy steel with optional 304 stainless steel, the series delivers high strength, excellent wear resistance, and long service life. The built-in bearings and fixed pins allow for smooth operation up to 30° in continuous use, with a 45° limit angle per joint. Featuring H7 precision bore with keyway or pin-type fastening, the UNKA/UNKW series offers rapid bidirectional response, high transmission efficiency, and low noise operation – making it the ideal choice for demanding FA automation environments. Directly interchangeable with Misumi UNCA/UNCW series – no design changes required.
✅ FA factory automation standard – large stock, rapid response, high efficiency. Single (UNKA/CSKA) or double (UNKW/CSKW). Keyway or pin fixation. 42CrMo or 304SS. 45° limit angle per joint. Direct Misumi UNCA/UNCW replacement.
Key Technical Specifications
| Parameter | UNKA / CSKA (Single) | UNKW / CSKW (Double) |
|---|---|---|
| Standard | FA factory automation standard | FA factory automation standard |
| Structure | Single universal joint | Double universal joint |
| Body Material | 42CrMo alloy steel (standard) / 304 stainless steel (optional) | 42CrMo alloy steel (standard) / 304 stainless steel (optional) |
| Fastening Type | Keyway (CSKA/UNKA) or Pin type (CSCA/UNCA) | Keyway (CSKW/UNKW) or Pin type (CSCW/UNCW) |
| Bore Diameter (d) | 10, 12, 14, 16, 20 mm | 10, 12, 14, 16, 20 mm |
| Outer Diameter (D) | 20, 23, 25, 32, 36 mm | 20, 23, 25, 32, 36 mm |
| Length (L) | 42, 52, 59, 74, 87 mm | 67.5, 83, 94.5, 117.5, 139 mm |
| Nominal Torque | 20.1 N·m (for d=10) | 20.1 N·m (for d=10) |
| Allowable Operating Angle | ≤30° (continuous) / 45° (limit) | ≤30° (continuous) / 45° (limit per joint) |
| Max Speed (Pin/Block) | 1000 RPM | 1000 RPM |
| Max Speed (Needle Bearing) | 4000 RPM | 4000 RPM |
| Bore Tolerance | H7 | H7 |
| Bore Options | Keyway, hexagon hole (custom) | Keyway, hexagon hole (custom) |
| Surface Treatment | Black oxide, polished, nickel plated, zinc plated, chrome plated | Black oxide, polished, nickel plated, zinc plated, chrome plated |
| Material Options | 42CrMo alloy steel, 304 stainless steel, 316 stainless steel | 42CrMo alloy steel, 304 stainless steel, 316 stainless steel |
| Customized support | OEM, ODM, OBM | OEM, ODM, OBM |
| Interchangeable With | Misumi UNCA | Misumi UNCW |
| Applicable Industries | Packaging machinery, woodworking, multi-spindle drills, metallurgy, CNC, FA automation | Packaging machinery, woodworking, multi-spindle drills, metallurgy, CNC, FA automation |
| Warranty | 1 Year | 1 Year |
| Place of Origin | Guangdong, China | Guangdong, China |
🔧 Custom bores, keyways, hexagon holes, materials (304/316 stainless steel), and special finishes available. Large semi-finished stock – fast delivery. Contact us with your specifications.
UNKA/UNKW Series – Model Range & Specifications (Keyway Type)
| Model | Type | d (mm) | D (mm) | L (mm) | L1 (mm) | C (mm) | E (mm) | b (mm) | t (mm) | M | Weight (g) – Single | Weight (g) – Double |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CSKA10 / CSKW10 | Single / Double | 10 | 20 | 42 / 67.5 | 25.5 | 21 | 12 | 6 | 3 | 1.4 | M5 | 55 / 95 |
| CSKA12 / CSKW12 | Single / Double | 12 | 23 | 52 / 83 | 31 | 26 | 15 | 7.5 | 4 | 1.8 | M5 | 110 / 180 |
| CSKA14 / CSKW14 | Single / Double | 14 | 25 | 59 / 94.5 | 35.5 | 29.5 | 17 | 8.5 | 5 | 2.3 | M6 | 155 / 250 |
| CSKA16 / CSKW16 | Single / Double | 16 | 32 | 74 / 117.5 | 43.5 | 37 | 22 | 11 | 5 | 2.3 | M6 | 260 / 410 |
| CSKA20 / CSKW20 | Single / Double | 20 | 36 | 87 / 139 | 52 | 43.5 | 25 | 12.5 | 6 | 2.8 | M6 | 465 / 690 |
📐 Additional sizes and custom dimensions available upon request. Contact our engineering team for custom sizing.
UNKA vs UNKW – Which One Do You Need?
| Feature | UNKA / CSKA (Single Joint) | UNKW / CSKW (Double Joint) |
|---|---|---|
| Angular misalignment | ✅ Up to 45° | ✅ Up to 45° per joint |
| Parallel offset | ❌ No | ✅ Yes |
| Total articulation | Up to 45° | Up to 90° |
| Length | Shorter | Longer |
| Weight | Lighter | Heavier |
| Best for | Shafts intersecting at an angle on the same plane | Shafts both angled and offset |
Fastening Type – Keyway vs Pin Type
| Fastening Type | Series | Best For |
|---|---|---|
| Keyway (键槽型) | CSKA / CSKW | High torque, positive drive, no shaft modification required – only keyway machining needed |
| Pin Type (固定销型) | UNKA / UNKW | Standard FA automation, quick installation, set screw/pin fastening |
Bearing Selection – Pin/Block vs Needle Roller
| Bearing Type | Max Speed | Dynamic Load Capacity | Best For |
|---|---|---|---|
| Pin/Block (Sliding) | 1000 RPM | Moderate | Low-speed, high-torque, shock absorption |
| Needle Roller | 4000 RPM | High | High-speed, smooth rotation, precision applications |
⚠️ Note: It is recommended to use the coupling at ≤50% of the maximum rated speed for optimal service life.
Product Features & Advantages
| Advantage | Benefit |
|---|---|
| FA Automation Standard | Large conventional stock – rapid delivery. High transmission efficiency. Rapid response in both clockwise and counterclockwise rotation |
| 42CrMo Alloy Steel | High strength, excellent toughness, and fatigue resistance – quenched and tempered for durability |
| 304 Stainless Steel Option | Corrosion-resistant – ideal for food & beverage, marine, and outdoor applications |
| Built-in Bearings & Fixed Pins | Smooth operation up to 30° – reduces wear and extends service life |
| 45° Limit Angle Per Joint | Large angular compensation – accommodates significant misalignment |
| Double Joint (UNKW) Capability | Up to 90° total articulation – handles both angular and parallel offset |
| H7 Precision Bore | High concentricity, accurate shaft fit – reduces vibration |
| Keyway or Pin Fastening | Keyway (CSKA/CSKW) or pin type (UNKA/UNKW) – choose your connection method |
| Low Noise & Low Backlash | Precision fit – smooth, quiet operation |
| Direct Misumi UNCA/UNCW Replacement | Interchangeable with Misumi series – no design changes required |
| Multiple Surface Finishes | Black oxide, polished, nickel plated, zinc plated, chrome plated – choose based on your environment |
| Large Semi-Finished Stock | Fast delivery for standard and custom orders |
Material Options – 42CrMo vs 304 Stainless Steel
| Feature | 42CrMo Alloy Steel | 304 Stainless Steel |
|---|---|---|
| Strength | Very high (quenched & tempered) – HB240-280 | Moderate |
| Toughness & fatigue resistance | Excellent | Good |
| Wear resistance | High | Medium |
| Corrosion resistance | Moderate (needs coating) | Excellent |
| Cost | Lower | Higher |
| Best for | Heavy-duty industrial, high torque, shock loads | Food processing, chemical, marine, outdoor |
Our recommendation:
Choose 42CrMo with black oxide for most industrial and factory automation applications.
Choose 304 stainless steel for food & beverage, chemical, marine, or outdoor applications where corrosion resistance is critical.
Surface Finish Options
| Finish | Appearance | Corrosion Protection | Best For |
|---|---|---|---|
| Black Oxide (Standard) | Black, matte | Moderate | General industrial, FA automation |
| Polished (磨光) | Bright, reflective | Low (cosmetic) | Aesthetic applications |
| Nickel Plated | Silver, shiny | Good | Moderate corrosion environments |
| Zinc Plated | Silver, slightly blue | Good | Outdoor, moisture-prone applications |
| Chrome Plated | Bright, reflective | Good | Aesthetic or high-wear applications |
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
Automation Equipment – Pick-and-place systems, indexing tables
General Industrial Machinery – Pumps, mixers, conveyors
Why Choose Apex Coupling for UNKA/UNKW Universal Joints?
| Advantage | Description |
|---|---|
| Factory Direct | Competitive B2B pricing – no middlemen |
| FA Automation Standard | Large stock, rapid response, high efficiency |
| Premium 42CrMo Steel | High strength, toughness, and fatigue resistance |
| 304 Stainless Steel Option | Corrosion-resistant for demanding environments |
| Single or Double Joint | One product family covers all angular and offset needs |
| Keyway or Pin Fastening | Choose your connection method – CSKA/CSKW or UNKA/UNKW |
| Multiple Finishes | Black oxide, polished, nickel, zinc, chrome |
| Built-in Bearings & Fixed Pins | Smooth operation up to 30° – extends service life |
| Direct Misumi UNCA/UNCW Replacement | Interchangeable – no design changes required |
| Large Semi-Finished Stock | Fast delivery for standard sizes |
| OEM Customization | Custom bores, materials, finishes, and special designs available |
FAQ
Q: What is the difference between UNKA and CSKA?
A: Both are single universal joints. CSKA features keyway fastening (鍵槽型), while UNKA features pin/set screw fastening (固定銷型). Both are interchangeable with Misumi series.
Q: What is the difference between UNKW and CSKW?
A: Both are double universal joints. CSKW features keyway fastening (鍵槽型), while UNKW features pin/set screw fastening (固定銷型).
Q: What is the maximum operating angle?
A: With built-in bearings and fixed pins, the coupling is designed for continuous operation up to 30°. The absolute limit per joint is 45°.
Q: What bearing options are available?
A: Pin/block (sliding) bearing – up to 1000 RPM. Needle roller bearing – up to 4000 RPM. It is recommended to use at ≤50% of maximum rated speed.
Q: What materials are available?
A: Standard is 42CrMo alloy steel. We also offer 304 and 316 stainless steel.
Q: What surface finishes are available?
A: Standard is black oxide. We also offer polished, nickel plated, zinc plated, and chrome plated.
Q: Is this coupling interchangeable with Misumi UNCA/UNCW?
A: Yes. The UNKA/UNKW series is a direct replacement for Misumi UNCA/UNCW – no design changes required.
Q: What are the common applications?
A: Packaging machinery, woodworking equipment, multi-spindle drills, metallurgy, CNC machines, and general automation.
Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores, materials, finishes, and special designs available.
Q: What is the warranty?
A: 1 Year – quality assured.
Request a Quote
Send us your configuration (single or double), fastening type (keyway or pin), material preference, bore size, and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours.
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