Bolt Shear Stress Calculator
A free, browser-based calculator. Runs entirely in your browser — no sign up, nothing stored.
Enter Values
How to use this calculator
- Enter the shear force V across the bolt, in kN.
- Enter the bolt diameter d in mm.
- Set the number of shear planes (1 for single shear, 2 for double), then read the shear stress.
How it works
The Bolt Shear Stress Calculator finds the average shear stress in a bolt loaded across its axis.
τ = V / (n·A), where A = π·d²/4 is the nominal shank area and n is the number of shear planes. Double shear halves the stress because two cross-sections carry the load.
Worked example
20 kN, M16, double shear. A = π×16²/4 = 201 mm². τ = 20,000 ÷ (2 × 201) ≈ 49.7 MPa.
Frequently asked questions
Single vs double shear?
Single shear has one cross-section resisting the load; double shear has two (e.g. a bolt through three plates), so each plane carries half the force.
Should I use the thread or shank area?
This tool uses the nominal shank area. If the shear plane passes through the threads, designers use the smaller tensile-stress (thread) area — be conservative and check your code.
Can I use these results for final design?
No. These calculators are for first-pass sizing, checking and learning. They assume ideal supports, static loads and elastic behaviour, and they don't apply load factors, member capacity, buckling or connection checks. Always verify against the relevant design code (e.g. AS 4100, AS 1170, Eurocode) and have a qualified engineer sign off structural work.
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Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.