ECalc

Engineering calculators & reference


Bolt Length

Shortest standard bolt length that fully clamps a stack-up with washers and a nut.

L ≥ grip + washers + nut height + thread protrusion

Minimum: 0.884 in / 22.4 mm
Use standard: 1.000 in / 25.4 mm

Notes

  • Enter the total clamped thickness (sum of the layers under the head, plus any washers under the head you want to count) in inches or mm — tap the unit to switch.
  • Nut height and washer thickness come from the Hex Nut Sizes and standard SAE/ISO washer tables for the selected size.
  • Protrusion defaults to ~2 threads past the nut. The result is the next standard length at or above the computed minimum.