Minimum engagement for blind hole threads.
Applies to medium tolerance class (6 H)
Deviating tolerance classes require specific insertion lengths
| Bolt strength class Rate of thread d/P |
8.8 < 9 |
8.8 ≥ 9 |
10.9 < 9 |
10.9 ≥ 9 |
12.9 < 9 |
12.9 ≥ 9 |
| St 37 | 1.0 · d | 1.25 · d | ||||
| St 50, C 45 N, 46 Cr 2 N, 46 Cr 4 N |
0.9 · d | 1.0 · d | 1.2 · d | 1.4 · d | ||
| C 45 V, 46 Cr 4 V, 42 CrMo 4 V |
0.8 · d | 0.9 · d | 1.0 · d | 1.1 · d | ||
| d - | Thread O.D. [mm] Bolts with metric ISO-thread (standard thread) |
| P - | Pitch [mm] up to M 30: d/P < 9 > M 30: d/P ≥ 9 |