Tractors use large-module (4–8 mm) splines for PTO (power take-off) shafts where high torque and shock loads occur.
If you cannot access a full DIN 5480 PDF, you can use the following simplified formulas (always verify with official data for precision work):
Over-pins measurement: For external spline, measure over two pins of diameter d(_P) = 1.8×m (for m ≥ 2). The measurement M(_R) = d(_B) × cos α / cos α(_M) + d(_P), where α(_M) is involute function. Din 5480 Pdf
Beuth is the official sales arm of DIN. This is the most reliable source.
DIN 5480 is titled "Involute splines based on reference diameters" (German: Zahnwellen-Verbindungen mit Evolventenflanken – Bezugsdurchmesser). It superseded the older DIN 5463, DIN 5464, and DIN 5472 standards. Tractors use large-module (4–8 mm) splines for PTO
Key characteristics defined in the standard:
⚠️ Critical: Unlike ANSI B92.1 or ISO 4156, DIN 5480 does not use a pin or ball measurement as the primary control. It uses over-pin measurement (Mdk) but defines tolerances via the reference diameter concept. Over-pins measurement: For external spline, measure over two
A: No. For 45° involute splines, refer to ANSI B92.1 or ISO 4156 (which includes 45°).
If you download a zip file or a collection of DIN 5480 PDFs, you will notice it is split into multiple parts. It is crucial to know which part you need: