THK DPM Series Spline Nut

The THK DPM Series is a low-cost, flanged spline nut die-cast from a high-strength zinc alloy, built around a precision-rolled spline shaft. Unlike conventionally machined spline nuts, its sliding surface retains a wear-resistant chill layer formed during the rolling process, while the mating spline shaft is cold-rolled and mirror-finished to over 250 HV surface hardness for smooth, low-wear sliding motion. The specially shaped spline teeth offer a large contact area and strong concentricity, letting the shaft self-center under torque for stable, consistent torque transmission with rotational clearance held to 20 minutes of arc or less. Available across spline shaft diameters of 12 to 50 mm.