D-bore Couplings for Secure Torque Transmission on D-shafts

Marlborough, Massachusetts, USA, May 2026 – Ruland has introduced d-bore couplings designed to engage directly with d-profile shafting to prevent slippage in critical motion-control applications such as semiconductor equipment, medical devices, and factory or warehouse automation systems. The couplings are available in disc, jaw, bellows, and oldham styles, allowing engineers to select the coupling type best suited to their application requirements.

D-bore couplings provide a secure mechanical connection by mating directly with the flat on a D-shaft. Unlike set screw connections that may loosen or slip on small shafts, D-bore couplings engage directly with the shaft profile to provide secure torque transmission. Traditional set screw connections can also be difficult to install reliably on smaller shafts where the screw may not seat properly on the D-profile and may loosen due to vibration or improper installation.

These couplings are particularly useful on shafts under 7 mm where standard keyways are unavailable. By eliminating the need for secondary shaft machining while improving shaft engagement, D-bore couplings simplify assembly and improve reliability in compact motion control systems.

Ruland D-bore couplings are available with bore sizes ranging from 3 mm to 10 mm and are manufactured from aluminium for lightweight performance and low inertia. Clamp and set screw hub configurations are available depending on the coupling style.

Ruland manufactures its couplings in its Marlborough, MA, USA, advanced manufacturing facility from meticulously selected North American bar stock using proprietary manufacturing processes. All couplings are RoHS3-, REACH-, and Conflict Minerals-compliant.

For complete specifications, CAD models, and ordering information, visit www.ruland.com.

Summary:

• Direct d-shaft engagement prevents slipping in critical applications
• Available in disc, jaw, bellows, and oldham coupling styles
• Ideal for shafts under 7 mm where keyways are not available
• Carefully made in Ruland’s advanced manufacturing facility
• Available for immediate delivery
• RoHS3, REACH, and Conflict Minerals compliant

Picture:

Ruland d-bore couplings prevent slipping by engaging directly with D-shafting in precision motion control applications.

Source: Ruland Manufacturing Co., Inc. , http://www.ruland.com