| Dimension | Formula | Notes | | :--- | :--- | :--- | | | $m$ | Basic parameter | | Number of Teeth | $z$ | Basic parameter | | Reference Diameter | $d_B$ | $m \times z$ | | Base Circle Diameter | $d_b$ | $d_B \times \cos(30^\circ)$ | | Tip Diameter (External) | $d_a$ | $d_B + 2 \times m \times (h_aP^* + x)$ | | Root Diameter (External) | $d_f$ | $d_a - 2 \times h$ (varies by root fit) | | Circular Tooth Thickness | $s$ | $\fracm \times \pi2 + 2 \times x \times m \times \tan(\alpha_D)$ |
Letters F–G are slip fits; H is the standard line-on-line fit. Verified Resources and Standards din 5480 spline dimensions pdf verified
Since measuring tooth thickness directly is difficult, DIN 5480 documents typically provide verification via: | Dimension | Formula | Notes | |
For practical verification in a workshop, engineers use measurement over balls (or pins). A verified PDF provides the formula or constant values (M1 and M2) for calculating the measurement over 2 balls (internal) or 3 wires (external) according to DIN 5480-2. din 5480 spline dimensions pdf verified