Mechanical Stress Calculator
Axial, bending, shear, bearing and torsional stress in one tool — each shown in psi, ksi, MPa and Pa, with a safety factor and a yield check when you pick a material.
Mechanical Stress, Not Just F ÷ A
Stress is internal force per unit area, but it arrives in five very different forms depending on how the load is applied. A bolt in a clevis, a shaft under torque and a beam in bending all fail differently, so this calculator covers each one and then answers the real question: does it survive? Pick a material and it returns a safety factor and flags anything past yield.
The Five Stress Types
| Type | Formula | Where it applies |
|---|---|---|
| Axial | σ = F / A | Tension or compression in a member |
| Bending | σ = M c / I | Beams and bars in flexure |
| Shear | τ = F / A | Pins and bolts (single or double shear) |
| Bearing | σ = F / (d t) | Bolts, pins, rivets, clevis joints |
| Torsional | τ = T c / J | Shafts under torque |
Safety Factor and the Yield Check
Once a material is selected the calculator divides its yield strength by the calculated stress:
A factor above 1 means the part is below yield; below 1 means it would yield. Most designs target 1.5 to 3 or more depending on the loading, the code, and how well the loads are known. The result is colour-coded and warns when stress passes yield.
Yield Strength Reference
Typical yield strengths in the material library:
| Material | Yield (MPa) | Yield (ksi) |
|---|---|---|
| Titanium Ti-6Al-4V | 880 | 128 |
| 1018 Steel (cold drawn) | 370 | 53.7 |
| 6061-T6 Aluminum | 276 | 40 |
| A36 Steel | 250 | 36 |
| 304 Stainless | 215 | 31 |
| Brass | 200 | 29 |
| Copper (annealed) | 70 | 10 |
Frequently Asked Questions
Single shear vs double shear?
In double shear the load is carried across two cross-sections instead of one, so the shear area doubles and the stress halves. The calculator has a toggle for it.
Why does metric use millimetres?
Using newtons and millimetres makes stress come out directly in MPa, since 1 N/mm² equals 1 MPa. It is the standard mm-N-MPa system and avoids unit slips. Imperial uses pounds-force and inches for psi.
Yield or ultimate strength?
This tool compares against yield, the point where permanent deformation begins. Some designs instead factor against ultimate (fracture) strength – check which your code requires.
Related calculators
- Mechanical Force Calculator — the forces that create the stress.
- Torque Calculator — torque for torsional stress.
- Beam Deflection Calculator — deflection alongside bending stress.
- Moment of Inertia Calculator — the I and J these formulas need.
- Factor of Safety Calculator — dig deeper into margins.