W/(m·K) to Stokes Converter
Quickly convert from W/(m·K) to Stokes.
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Engineering unit conversions span stress, pressure, modulus of elasticity, strain, torque, and more — the quantitative language of structural, mechanical, and materials engineering.
Where is it used?
• Structural Engineering — Beam stress calculations, concrete compressive strength (MPa or psi), and steel yield strength (GPa or ksi) require consistent unit systems across international design codes.
Examples:
• 1 MPa = 145.038 psi
• 1 psi = 6,894.76 Pa
Engineering unit conversions connect analysis, design, and manufacturing across structural, mechanical, and materials workflows. Daily calculations involve stress, strain, modulus, pressure, torque, and load in mixed SI and imperial systems (Pa/MPa/GPa, N·m, psi/ksi), where small conversion errors can propagate into major safety and performance risks.
Engineering covers a wide range of derived mechanical quantities. Stress and pressure share the same SI unit, the Pascal (Pa), representing force per unit area. Modulus of elasticity (Young's modulus, E) uses the same units as stress (Pa or GPa) and describes a material's stiffness. Strain is dimensionless (deformation per unit length). Torque is measured in Newton-metres (N·m). US customary engineering still widely uses psi (pounds per square inch), ksi (1,000 psi), and ft·lbf for torque.
Where is it used?
- Structural Engineering — Beam stress calculations, concrete compressive strength (MPa or psi), and steel yield strength (GPa or ksi) require consistent unit systems across international design codes.
- Materials Science — Young's modulus, shear modulus, and bulk modulus are specified in GPa for metals (steel ~200 GPa, aluminium ~70 GPa) and MPa for polymers and composites.
- Mechanical Design — Bolt torque specifications (N·m or ft·lbf), bearing load ratings (kN), and shaft stress analysis mix SI and US customary units depending on the standard used.
- Geotechnical & Civil Engineering — Soil bearing capacity and pile design use kPa or ksf (kips per square foot); hydraulic pressures in dams use MPa.
- Automotive & Aerospace — Engine torque (N·m or ft·lbf), material fatigue limits (MPa), and pressure vessel ratings (bar or psi) must be converted precisely for safety-critical components.
Common Conversion Mistakes
Confusing pressure and stress units
Pressure and stress both use Pa (N/m²), but stress in engineering materials is typically expressed in MPa or GPa. A steel yield strength of 250 MPa = 250,000,000 Pa = 36,260 psi. Forgetting the mega/giga prefix leads to errors of 6 orders of magnitude.
Mixing up kPa, MPa, and bar
1 bar = 100 kPa ≈ 0.1 MPa ≈ 14.5 psi. These are close but not equal. Atmospheric pressure is ~101.325 kPa (1 atm) or ~1.013 bar. Substituting bar for MPa without correction introduces a 0.3% error that matters in precision engineering.
Confusing torque N·m with energy J (both are N·m)
Torque and energy have the same dimensional units (N·m = J) but are physically distinct. Torque is a vector moment; energy is a scalar. Never convert between them — a torque of 100 N·m does not mean 100 J of energy stored.
Ignoring gauge vs. absolute pressure
Pressure gauges read gauge pressure (relative to atmosphere). Absolute pressure = gauge pressure + atmospheric pressure (~101.325 kPa). In engineering calculations involving gas laws or compressor performance, always clarify whether pressures are gauge (psig, barg) or absolute (psia, bara).
Quick Reference Table
| From | To |
|---|---|
| 1 MPa | 145.038 psi |
| 1 psi | 6,894.76 Pa |
| 1 ksi | 6.895 MPa |
| 1 GPa | 145,038 psi ≈ 145 ksi |
| 1 N·m (torque) | 0.7376 ft·lbf |
| 1 ft·lbf | 1.3558 N·m |
| 1 bar | 100 kPa = 14.504 psi |
| 1 atm | 101.325 kPa = 14.696 psi |
Frequently Asked Questions
What is the difference between stress and pressure?
Both are force per unit area (Pa), but pressure is typically isotropic (acts equally in all directions in a fluid), while stress in a solid is a tensor — it has both normal components (tension/compression) and shear components. In structural analysis, the full stress state at a point requires six independent stress components, not just one number.
What does Young's modulus tell me about a material?
Young's modulus (E) describes stiffness: how much a material deforms under a given stress. E = stress/strain. Steel has E ≈ 200 GPa, aluminium ≈ 70 GPa, concrete ≈ 30 GPa, rubber ≈ 0.01–0.1 GPa. A higher E means the material deforms less for the same load — useful for beams and columns where deflection must be minimised.
How do I convert between psi and MPa quickly?
A useful approximation: 1 MPa ≈ 145 psi, or 1 psi ≈ 6.895 kPa. For quick mental conversion: multiply MPa by 145 to get psi, or divide psi by 145 to get MPa. For example, a 60,000 psi (60 ksi) steel yield strength ≈ 414 MPa.
Why is torque specified in both N·m and ft·lbf?
The automotive and aerospace industries in the US predominantly use ft·lbf (or in·lbf for small fasteners), while European and international standards use N·m. A wheel lug nut torqued to 100 N·m = 73.8 ft·lbf. Always match the specification sheet's unit system; a 26% conversion error from confusing the two could strip threads or cause under-tightening.
Sources & Standards
- ASTM International — Standard unit definitions for mechanical testing
- ISO 80000-4 — Quantities and units: mechanics
- American Institute of Steel Construction (AISC) Steel Construction Manual
- National Institute of Standards and Technology (NIST) — SI guide for engineering
Reviewed by The Unit Hub Editorial Team · March 2026