Conversion tricks and mini tools
Top 10 engineering conversion checks
Engineering reviews should include dimensional analysis: stress units, pressure in gauge vs absolute, torque angles, and thermal expansion coefficients in consistent systems.
If equations mix MPa, psi, and bar in one paragraph, reviewers should stop and normalize before approving release.
Key takeaways
- Gauge vs absolute: add/subtract atmospheric pressure explicitly for thermo calcs.
- Torque + angle sequences stay paired—do not swap N·m with lb·ft casually.
- Thermal expansion: temperature deltas must use the coefficient’s stated scale.
- Reynolds and dimensionless groups need one coherent unit system for inputs.
How to convert
2.3 Bar = 33.358667 psi
Stress and pressure vocabulary
Clarify MPa vs psi vs bar in the same paragraph when teams merge; do not rely on context memory.
Gauge vs absolute in pneumatics
Add or subtract atmospheric pressure explicitly when converting to SI absolute for calculations.
Torque and angle pairs
Record N·m plus degrees of turn for bolt procedures; do not interchange with lb·ft without tool calibration context.
Thermal expansion
Coefficients are per degree in a stated scale—convert temperature deltas before applying length change formulas.
Sign-off checklist item
Add “units verified on every equation” as a required reviewer tick for cross-border projects.
Reynolds number and units
Dimensionless groups only stay dimensionless if length, velocity, density, and viscosity use one coherent system—convert inputs before coding.
Hydraulic hose ratings
Burst pressure may be in psi while fittings are torque spec’d in N·m—document both on the same work instruction.
Fatigue S–N curves
Stress amplitude units on legacy charts may be ksi; convert to MPa for FEA comparison without mixing log-scale axes.