Design safer parts using strength and stress inputs. Include load and material factors easily here. Compare margins, then export neat CSV and PDF reports.
| Strength basis | Strength | Stress method | Applied stress | Load factor | Material factor | Target n | Computed n |
|---|---|---|---|---|---|---|---|
| Yield strength | 250 MPa | Direct | 80 MPa | 1.20 | 1.10 | 2.00 | 2.366 |
| Ultimate strength | 550 MPa | Load/Area | 1200 N / 20 mm² | 1.10 | 1.05 | 3.00 | 7.920 |
| Shear strength | 300 MPa | Direct | 140 MPa | 1.00 | 1.20 | — | 1.786 |
Safety factor compares available capacity to stress demand. It adds margin when loads vary, properties scatter, or service conditions reduce strength. The selected value should reflect failure consequences, inspection capability, and confidence in your assumptions.
The tool combines a material strength with an applied stress. Stress can be entered directly or computed as average normal stress from load and area. Optional load and material factors adjust demand and capacity to represent uncertainty without changing units. Use consistent units; the calculator converts common stress and force units.
Use yield strength for ductile materials when permanent deformation is unacceptable. Use ultimate strength when fracture is limiting or ductility is low. For repeated loading, use a fatigue allowable or endurance limit. Always match the basis to the failure mode you must prevent.
With load and area, the calculator uses σ = F/A, giving a first estimate for axial members, bolts in tension, and average bearing stress. If bending, stress concentrations, or multiaxial effects matter, compute stress from analysis or testing and enter that value instead.
Load factors represent overloads, dynamics, and uncertainty in operating forces. Material factors represent strength variability, temperature, corrosion, and manufacturing effects. Here, the load factor multiplies stress and the material factor divides strength, producing a stricter, more conservative check.
With a target safety factor, allowable stress is computed as effective strength divided by the target. This helps set stress limits during sizing. Required strength mode reverses the relationship to estimate what nominal strength you need to meet the target under factored loading.
Targets depend on consequence of failure, variability, and how well you can inspect or monitor the part. Static, well-known loading often permits lower targets, while brittle materials, variable loading, or safety-critical parts require higher targets. Follow applicable standards and internal design rules. If you have test data and tight quality control, you may justify smaller margins.
Record the strength basis, factors, and computed safety factor alongside assumptions on load case, environment, and data sources. Export CSV for design logs and comparisons, and export PDF for reviews and sign-off packs. Clear documentation makes future changes and audits faster.
It means the effective material capacity is twice the effective stress demand for the chosen basis. It does not guarantee zero risk, but it provides margin against uncertainty.
Use yield strength for ductile metals where permanent set is unacceptable. Use ultimate strength when fracture governs or deformation is allowed. For brittle materials, ultimate-based limits are often safer.
Use load and area for simple axial loading or average pressure estimates. If bending, stress concentrations, or complex stress states exist, calculate stress with analysis or testing and enter it directly.
The load factor multiplies stress to represent worst-case loading, dynamics, or uncertainty. A higher load factor reduces the computed safety factor and produces a more conservative design check.
The material factor divides strength to represent variability, defects, temperature, corrosion, or manufacturing effects. A higher material factor reduces effective strength and increases conservatism.
It can support fatigue checks if you enter an appropriate fatigue allowable strength and representative stress amplitude. Full fatigue design also needs cycle counts, mean-stress effects, and S–N or strain-life data.
Pass means the computed safety factor meets the target, or exceeds one when no target is given. Check means the margin is below the target, suggesting changes to sizing, loading, or material choice.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.