Ruland DCD21-8-6-A Aluminum Disc Double Disc Clamp Coupling 1/2 in x 3/8 in Bores.
Ruland DCD21-8-6-A Aluminum Disc Coupling, Double Disc Clamp Style, 0.500″ x 0.375″ Bores, 1.313″ OD.
| Dimensions | |||
|---|---|---|---|
| Bore (B1) | 0.5000 in | Small Bore (B2) | 0.3750 in |
| B1 Min Shaft Penetration | 0.354 in | B2 Min Shaft Penetration | 0.354 in |
| B1 Max Shaft Penetration | 0.842 in | B2 Max Shaft Penetration | 0.842 in |
| Outer Diameter (OD) | 1.313 in (33.3 mm) | Bore Tolerance | +0.001 in / -0.000 in |
| Length (L) | 1.770 in (45.0 mm) | Hub Width (LH) | 0.590 in |
| Recommended Shaft Tolerance | +0.0000 in / -0.0005 in | ||
| Fastening Hardware | |||
| Forged Clamp Screw | M3 | Screw Material | Alloy Steel |
| Hex Wrench Size | 2.5 mm | Screw Finish | Black Oxide |
| Seating Torque | 2.1 Nm | Number of Screws | 2 ea |
| Performance Specifications | |||
| Dynamic Torque Reversing | 25 lb-in | Angular Misalignment | 2.0° |
| Dynamic Torque Non-Reversing | 50 lb-in | Parallel Misalignment | 0.008 in |
| Static Torque | 100 lb-in | Axial Motion | 0.016 in |
| Torsional Stiffness | 253 lb-in/Deg | Moment of Inertia | 0.0443 lb-in2 |
| Maximum Speed | 10,000 RPM | Full Bearing Support Required? | Yes |
| Average Load at Max Parallel Offset | 2.46 lbf | Average Slope | 281.08 lbf/in |
| Zero-Backlash? | Yes | Balanced Design | Yes |
| Recommended Installation Tools | |||
| Torque Wrench | TW:BT-1R-1/4-18.3 | Recommended Hex Key | Metric Hex Keys |
| Additional Information | |||
| Material Specification | Hubs and Center Spacer: 2024-T351 Aluminum Bar Disc Springs: Type 302 Stainless Steel | Temperature | -40°F to 200°F (-40°C to 93°C) |
| Finish Specification | Sulfuric Anodized MIL-A-8625 Type II, Class 2 and ASTM B580 Type B Black Anodize | Manufacturer | Ruland Manufacturing |
| Country of Origin | USA | Weight (lbs) | 0.180900 |
| UPC | 634529081785 | Tariff Code | 8483.60.8000 |
| UNSPC | 31163008 | ||
Ruland disc couplings are zero-backlash, torsionally stiff, and have a balanced design. They are manufactured in single disc styles for compact installations and double disc styles for increased misalignment capabilities. They are made from black anodized aluminum hubs and multiple flat stainless steel disc springs.
Double disc styles also include a center spacer allowing the coupling to accommodate all forms of misalignment including parallel. They are well suited for high precision positioning systems found in semiconductor, solar, printing, and machine tools.Combining aluminum hubs with stainless disc springs results in a lightweight, low inertia coupling that is well suited for precision applications found in a variety of industries including semiconductor, solar, printing, and machine tools.
Disc couplings are a simple assembly with few moving parts reducing the risk for coupling failure and backlash. Ruland uses a balanced design to reduce vibration in high RPM applications of up to 10,000 PRM. Ruland disc couplings are carefully made from select bar stock sourced exclusively from North American mills and are machined to a fine burr-free finish.
Hardware tests beyond DIN 912 12.9 standards for maximum torqueing capabilities. Ruland, founded in 1937, manufactures all products in our Marlborough, MA USA factory under strict controls using proprietary processes. Disc couplings are RoHS2 and REACH compliant.
