🎥 Video — Torque Calculator & Complete Guide — Formula, Units, and How Torque Creates Linear Force
Engineering notes for torque
Torque is the turning effect created by force at a distance. The distance matters as much as the force.
Robbie Dickson-style engineering note: do the simple calculation first, then check the ugly real-world parts: mounting stiffness, friction, duty cycle, tolerances, and what happens when the mechanism is at its worst angle.
Core formula
Torque = force x moment arm. Use consistent units, such as lb-in, N-m, or oz-in.
Worked calculation example
If a 150 lb load acts 4 inches from a pivot, the static torque is 600 lb-in. With a 1.5 safety factor, size the drive or actuator geometry for at least 900 lb-in before friction and acceleration are added.
Selection table
| Case | Engineering effect | Practical use |
|---|---|---|
| Static load | Weight held without acceleration | Start with force x distance |
| Moving load | Acceleration and direction changes | Add inertia and safety factor |
| Poor angle | Actuator nearly inline with linkage | Expect force demand to rise sharply |
Practical checks before choosing parts
- Confirm the load path and the worst-case position, not only the average position.
- Use consistent units through the full calculation and write down every assumption.
- Add a safety factor for friction, wear, impact, unknown loading, and mounting flex.
- Check duty cycle, current draw, heat, and bracket strength before treating the result as final.
- Bench test the mechanism when the cost of being wrong is higher than the cost of a quick prototype.
Useful FIRGELLI resources to cross-check
- Bolt Torque Calculator Preload And Clamp Force - Shared topic terms: force, torque
- Force Torque Sensor Resolution Checker - Shared topic terms: force, torque
- Lead Screw Torque And Force Calculator - Shared topic terms: force, torque
- Linear Actuator Force Calculator Incline With Friction - Shared topic terms: force, linear
- Linear Actuator Speed Vs Force Tradeoff Calculator - Shared topic terms: force, linear
- Screw Jack Calculator Lifting Force And Torque - Shared topic terms: force, torque
FAQ
Why does actuator angle change torque so much?
Only the perpendicular component of force creates torque. As the actuator gets closer to inline with the arm, mechanical advantage drops.
Should I use peak or continuous torque?
Use continuous torque for repeated duty. Peak torque is only useful for short transients if temperature and current limits are acceptable.
What safety factor is reasonable?
For first-pass sizing, 1.5 is common for clean loads. Use more when impact, binding, unknown friction, or people are nearby.
