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.
is the German industrial standard for involute splines based on reference diameters. It defines the geometry, dimensions, and tolerances for spline joints where the teeth have an involute profile, similar to gear teeth, ensuring high torque transmission and self-centering capabilities. Core Technical Specifications Pressure Angle : Strictly limited to 30° . Din 5480 Pdf
Some notations also include a centering feature: e.g., DIN 5480 – N 45 x 2 x 21 x 9H where N indicates major diameter centering. For external spline, measure over two pins of
Free calculators can give you approximate dimensions, but they rarely include the complete tolerance system or the inspection nuances. For prototype work, a calculator might suffice. For serial production, It defines the geometry, dimensions, and tolerances for