$142.52 ea
Quantity Price (USD)
1 $142.52 ea
10 $106.89 ea
25 $79.81 ea
50 $47.92 ea
100 Request Quote
Built to Order Lead Time: 0-2 Days
Ruland DSSK21-10-5-A, 5/8" x 5/16" Single Disc Coupling, Aluminum, Set Screw Style With Keyway, 1.313" OD, 1.313" Length


Ruland DSSK21-10-5-A is a single disc coupling with 5/8" x 5/16" bores, 1.313" OD, 1.313" length, and 3/16" keyway on the 5/8" bore and no keyway on the 5/16" bore. It is zero-backlash and has a balanced design for reduced vibration at high speeds. The single disc design is comprised of two anodized aluminum hubs and two sets of thin stainless steel disc springs which can accommodate angular misalignment and axial motion, however does not allow for any parallel misalignment. DSSK21-10-5-A is lightweight and has low inertia making it well suited for applications with speeds up to 10,000 RPM. Hardware is metric and tests beyond DIN 912 12.9 standards for maximum torque capabilities. Ruland manufactures DSSK21-10-5-A to be torisionally rigid and an excellent fit for precise positioning stepper servo applications commonly found in semiconductor, solar, printing, machine tool, and test and measurement systems. It is machined from solid bar stock that is sourced exclusively from North American mills and RoHS2 and REACH compliant. DSSK21-10-5-A is manufactured in our Marlborough, MA factory under strict controls using proprietary processes.



Large Bore B1

0.625 in

Small Bore B2

0.313 in

B1 Shaft Penetration

0.590 in

B2 Shaft Penetration

0.635 in

Keyway K

3/16 in

Keyway K2


Bore Tolerance

+.001 in / -.000 in

Outer Diameter OD

1.313 in

Length L

1.313 in

Hub Width LH

0.590 in

Fastening Hardware

Forged Set Screw


Number of Screws

4 ea

Screw Material

Alloy Steel

Screw Finish

Black Oxide

Hex Wrench Size

2.0 mm

Seating Torque

2.2 Nm

Performance Specifications

Static Torque

100 lb-in

Angular Misalignment


Dynamic Torque Non-Reversing

50 lb-in

Parallel Misalignment

0.00 in

Dynamic Torque Reversing

25 lb-in

Axial Motion

0.008 in

Torsional Stiffness

313 lb-in/Deg

Maximum Speed

10,000 RPM

Additional Information

Material Specification

Hubs: 2024-T351 Aluminum Bar, Disc Springs: Type 302 Stainless Steel


-10°F to 200°F
-23°C to 93°C

Finish Specification

Sulfuric Anodized MIL-A-8625 Type II, Class 2 and ASTM B580 Type B Black Anodize


Ruland Manufacturing

Country of Origin


Weight (lbs.)




Product Notes

Note 1

Stainless steel hubs are available upon request.

Note 2

Torque ratings are at maximum misalignment.

Note 3

Performance ratings are for guidance only. The user must determine suitability for a particular application.

Note 4

Torque ratings for the couplings are based on the physical limitations/failure point of the disc springs. Under normal/typical conditions the hubs are capable of holding up to the rated torque of the disc springs. In some cases, especially when the smallest standard bores are used or where shafts are undersized, slippage on the shaft is possible below the rated torque of the disc springs. Keyways are available to provide additional torque capacity in the shaft/hub connection when required. Please consult technical support for more assistance.

Prop 65

WARNING This product can expose you to chemicals including Ethylene Thiourea and Nickel (metallic), known to the State of California to cause cancer, and Ethylene Thiourea known to the State of California to cause birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

ISO 9001:2015


Conflict Minerals






We found other products you might like!


© 2018 Ruland Manufacturing Co., Inc. All rights reserved