EngiRef / Metric Bolt Specification

M24

M24 coarse-thread metric bolt: 3 mm pitch, 24 mm major diameter. Tensile stress area 353 mm² per ISO 898-1. Takes a 36 mm wrench. Free bolt specification table…

Specification

Size
M24
Pitch (mm)
3
Major diameter d (mm)
24
Minor diameter d₃ (mm, external thread)
20.32
Tensile stress area (mm²)
353
Head height (mm)
15
Head diameter (mm)
36
Wrench size (mm)
36

Tensile stress area follows ISO 898-1, At = (π/4)(d − 0.9382p)². Verify against the current standard and the fastener manufacturer's data before safety-critical design.