The newton-metre (also non-hyphenated, newton metre; also known as newton-meter; symbol N⋅m or N m In this usage the metre term represents the distance travelled or displacement in the direction of the force, and not the perpendicular distance from a fulcrum (i.e. the lever arm length) as it does when used to express torque. This usage is generally discouraged, since it can lead to confusion as to whether a given quantity expressed in newton-metres is a torque or a quantity of energy.
Newton-metres and joules are dimensionally equivalent in the sense that they have the same expression in SI base units,
: <math>1 \, \text{N} {\cdot} \mathrm{m} = 1 \, \frac{\text{kg} {\cdot} \text{m}^2}{\text{s}^2} \quad , \quad 1 \, \mathrm{J} = 1 \, \frac{\mathrm{kg} {\cdot} \mathrm{m}^2}{\mathrm{s}^2}</math>
but are distinguished in terms of applicable kind of quantity, to avoid misunderstandings when a torque is mistaken for an energy or vice versa. Similar examples of dimensionally equivalent units include Pa versus J/m<sup>3</sup>, Bq versus Hz, Watt versus Volt-ampere, and ohm versus ohm per square.
Conversion factors
- 1 kilogram-force-metre = 9.80665 N⋅m
<!-- Units of force, not of torque *1 pound-force = 0.45359237 kilogram-force -->
- 1 newton-metre ≈ 0.73756215 pound-force-feet
- 1 pound-foot ≡ 1 pound-force-foot ≈ 1.35581795 N⋅m
- 1 ounce-inch ≡ 1 ounce-force-inch ≈ 7.06155181 mN⋅m (millinewton-metres)
- 1 dyne-centimetre = 10<sup>−7</sup> N⋅m
See also
- Bending moment
- Spring scale
- Torque tester
- Newton-second, the SI unit of impulse