THK DP Series Spline Nut

The THK DP Series is a low-cost, cylindrical (flange-less) spline nut die-cast from a high-strength zinc alloy, built around a precision-rolled spline shaft. As with the flanged DPM, its sliding surface retains a wear-resistant chill layer from the rolling process, and the mating spline shaft is cold-rolled and mirror-finished to over 250 HV surface hardness for smooth, low-wear motion. The specially shaped spline teeth provide a large contact area and strong concentricity, allowing the shaft to self-center under torque for stable transmission, with rotational clearance held to 20 minutes of arc or less. Available across spline shaft diameters of 12 to 50 mm, suited to applications needing a compact, flange-less mounting profile.