Metric Rigid Couplings with Step Bores

Ruland Manufacturing Co., Inc.
October 2, 2016


Step bore rigid couplings are designed and engineered to have superior fit and holding power in precision servo applications as well as shaft-to-shaft connections.

Marlborough, MA - Ruland has expanded its line of rigid couplings to include metric sizes with step bores. This gives equipment manufacturers designing precision servo driven systems or shaft-to-shaft connections a wider range of standard in-stock products to choose from. The couplings are available in one- and two-piece clamp styles with or without keyways for superior fit and holding power.

Ruland supplies rigid coupling hardware with a proprietary coating called Nypatch to resist vibration and maintain holding power. Nypatch is applied 360 degrees around several threads of the socket head cap screws to prevent them from loosening under vibration, causing a reduction or loss of torque transmission during operation. It also provides for even seating of the screw, repeated installations and prevents galling. All metric hardware tests beyond DIN 912 standards for maximum torque capabilities.

Clamp type rigid couplings wrap evenly around the shaft to provide high torsional holding power without damage to the shaft caused by set screws. Two-piece clamp styles have a balanced design with opposing screws for reduced vibration and higher speed capabilities. They have the additional benefit of being able to come apart completely for in-place servicing without the need to remove additional components.

Metric rigid couplings are offered in sizes ranging from 3 mm to 50 mm. They are manufactured from bar stock in Ruland’s factory in Marlborough, Massachusetts, and are RoHS2 and REACH compliant. The Ruland name is stamped on each rigid coupling for ease of identification. Rigid couplings are made from 1215 lead-free steel or 303 stainless steel sourced from carefully selected North American mills to ensure product consistency.

Established in 1937, Ruland focuses on the design and manufacture of high performing shaft collars and couplings. All products are carefully manufactured in Marlborough, Massachusetts USA factory under strict controls using proprietary processes. 3D CAD files, full product specifications, and additional technical information, are available at

Product Link:  Rigid Couplings

Article Summary
• Standard step bore rigid couplings give machine designers more flexibility
• Supplied with Nypatch anti-vibration hardware to maintain holding power
• Two-piece styles have a balanced design for reduced vibration
• RoHS2 and REACH compliant
• RoHS2 and REACH compliant
• Carefully made in our Marlborough, Massachusetts factory and available for immediate delivery

Ruland Manufacturing Co., Inc.

PR Contact:
TPR International

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