Ruland and Reliance Precision have agreed to cooperate by offering Reliance designed and manufactured slit couplings through Ruland’s eCommerce platform and extensive worldwide distribution network. Ruland will stock and bore to size a wide selection of slit couplings in its Marlborough location. The addition of slit couplings gives Ruland a more complete zero-backlash coupling offering to complement its existing product line which includes rigid, beam, bellows, controlflex, disc, jaw, and oldham couplings.

Slit couplings are zero-backlash and manufactured from a single piece of aluminium with intermittent slit cuts allowing for high torque and torsional stiffness capabilities, low inertia, and long-life. Reliance’s design uses a proprietary slit pattern that has radiused as opposed to squared edges, reducing stresses that build up during misalignment conditions and torque loads. Equipment designers in industries such as packaging, scientific, semiconductor, solar, medical, and automation benefit from the wide range of sizes and performance characteristics offered by slit couplings.

Slit couplings offer designers a high-performance with a coupling that has a balance of torque, misalignment, and torsional stiffness capabilities. They have comparable torque to a single disc coupling, torsional stiffness to a stainless steel beam coupling, and misalignment to an aluminium beam coupling. Ruland offers slit couplings in RL- and RS-series. RL-series couplings have longer lengths allowing for greater parallel misalignment capabilities and increased torsional stiffness. RS-series couplings are designed to fit in compact spaces and offer parallel misalignment capabilities, an upgrade to the single disc coupling which has comparable torque but no accommodation for parallel misalignment. Both series can accommodate all forms of misalignment with low bearing loads. They have a zero-backlash balanced design allowing for speeds up to 70,000 rpm.

Slit couplings are available in clamp screw and set screw designs with inch, metric, and inch to metric bore sizes ranging from 1.5 mm to 12 mm and 1/8 inch to 3/8 inch. They are manufactured by Reliance Precision at their manufacturing facility in County Cork, Ireland. Hardware exceeds industry standards for maximum torque capabilities. Full product specifications including free downloadable CAD files can be found at


  • Lightweight, low inertia coupling capable of speeds up to 70,000 rpm
  • Manufactured from 7075 aluminium for a long zero-backlash life
  • High-performance coupling with a balance of torque, torsional stiffness and misalignment.
  • Sizes starting at 1.5 mm for applications with small shaft sizes and high speeds
  • Long styles for added torque and misalignment capabilities
  • Short styles for compact installations
  • RoHS3 and REACH compliant
  • Large inventory
  • Available for immediate delivery

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Slit Couplings