M5 Carriage Bolts are manufactured to DIN 603. This page lists the controlling dimensions for the M5 size together with the installation notes for this type.
M5 Dimensional Row (DIN 603)
| Size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Square neck width (mm) | Square neck depth (mm) | Common length range (mm) | Reference standard |
|---|---|---|---|---|---|---|---|
| M5 | 0.8 | 13.0 | 3.0 | 5.0 | 2.5 | 16~80 | DIN 603 / ISO 8677 |
Tightening Torque for M5
| Class 8.8 (dry, ~µ 0.125) | ≈ 5.8 Nm |
|---|---|
| Class 10.9 (dry, ~µ 0.125) | ≈ 8.1 Nm |
| Class 12.9 (dry, ~µ 0.125) | ≈ 9.7 Nm |
Indicative dry-joint values. Lubrication can lower the required torque by 15–25%. Always confirm against the joint design, especially when going up a strength class.
Proof Load & Strength for M5
| Tensile stress area As (ISO 898-1) | 14.2 mm² |
|---|---|
| Proof load, class 8.8 | 8.2 kN |
| Proof load, class 10.9 | 11.8 kN |
| Proof load, class 12.9 | 13.8 kN |
| Min. ultimate tensile, class 8.8 | 11.4 kN |
Proof load = stress area × proof stress per ISO 898-1. Design joints so the working preload stays below the proof load of the selected class.
Common Applications for M5 Carriage Bolts
M5 Carriage Bolts are commonly specified for precision instruments, small machinery and consumer-electronics enclosures.
Mating Parts for M5
For M5, pair with a M5 hex nut (ISO 4032 / DIN 934) and, where used, a M5 flat washer (ISO 7089 / DIN 125A) under the head and under the nut.
When to Step Up or Down from M5
When the joint preload approaches the proof load of M5 class 8.8, step up to M6 class 8.8 (or move to M5 class 10.9). When the joint is over-specified, M4 often saves weight and cost without losing the safety margin.
