The couplings comprise two anodised aluminium hubs and a torque transmitting centre disc, allowing a single coupling to combine clamp and set screw hubs with inch, metric, keyed and keyless bores. Ruland uses a proprietary hub machining process that leaves a smoother surface for interaction between the hub and disc, resulting in long life and reduced downtime.
Torque transmission is accomplished by mating the slots on the centre disc to the drive tenons on the hubs. The disc, which is a replaceable unit, is available in acetal for high torsional stiffness, PEEK for high temperature and low outgassing, and nylon for shock absorption and noise reduction. Oldham couplings are naturally electrically isolating due to the non-conductive nature of the centre disc.
Bore sizes range from 3mm to 30mm, and stainless steel hubs are available upon request for use in high corrosion or clean room environments. Discs can be manufactured with a centre hole to allow further shaft penetration or tapped holes to attach the disc to a hub so it stays in place during disassembly.