Torque Converter

While force is a push or pull in a straight line, torque is a rotational force that causes twisting or turning. Torque is calculated by multiplying the force by the distance from the pivot point (lever arm). For example, when using a wrench to tighten a bolt, you can increase the torque either by pushing harder (more force) or by using a longer wrench (greater distance). This is why longer wrenches make it easier to loosen tight bolts - they provide more torque for the same amount of force.

Different torque units evolved from different measurement systems and applications. Newton-meters (N⋅m) is the SI unit, commonly used in scientific and international contexts. Pound-feet (lb⋅ft) and pound-inches (lb⋅in) are popular in American automotive and machinery applications. Kilogram-force meters (kgf⋅m) is used in some Asian countries. The choice of unit often depends on the industry standard, the magnitude of torque being measured, and regional preferences. For example, small electronics might use ounce-inches, while car engines use pound-feet.

Torque specifications depend on the application, material properties, and safety requirements. For mechanical fasteners like bolts, the manufacturer typically provides specific torque values that ensure proper clamping force without damaging the components. For example, a car wheel lug nut might require 80-100 lb⋅ft, while a small electronic device screw might need only 2-3 in⋅oz. Always consult the manufacturer's specifications or technical documentation, and use a calibrated torque wrench when precise torque is critical for safety or function.