Definition and Usage of Newton-metre
- A newton-metre is the unit of torque or moment in the International System of Units (SI).
- It is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm that is one metre long.
- The unit is also used as a unit of work or energy, equivalent to the joule.
- The metre term represents the distance travelled or displacement in the direction of the force, not the perpendicular distance from a fulcrum.
- Torque and energy expressed in newton-metres can sometimes lead to confusion.

Relationship Between Newton-metre and Joule
- One newton-metre of torque is equivalent to one joule per radian.
- Newton-metres and joules are dimensionally equivalent in SI base units.
- The expression for one newton-metre is 1 Nm = 1 kg·m²/s².
- Distinguishing between torque and energy avoids misunderstandings.

Conversion Factors
- 1 kilogram-force metre is equal to 9.80665 Nm.
- 1 newton-metre is approximately equal to 0.73756215 pound-force-feet.
- 1 pound-foot is equal to 1.35581795 Nm.
- 1 ounce-inch is approximately equal to 7.06155181 mNm (millinewton-metres).
- 1 dyne-centimetre is equal to 10 Nm.

Related Concepts and Units
- Bending moment is a related concept to newton-metre.
- Spring scale is an instrument that measures forces in newtons.
- Torque tester is another related concept to newton-metre.
- Newton-second is the derived SI unit of impulse.
- The nonstandard notation Nm is sometimes used in certain fields.

References and Additional Information
- BIPM provides information on unit symbols.
- Eshbach's Handbook of Engineering Fundamentals mentions newton-metre as the basic unit of energy in SI units.
- The spring scale is a different instrument that measures forces in newtons.
- The concept of torque is related to newton-metre.
- The newton-second is another derived SI unit.