t·m²

tonne square meter

Moment of inertiaexact by definition

The tonne square metre is exactly 1000 kg·m². Flywheels, turbine rotors and ship propulsion trains are quoted in t·m², where the GD² of older machinery literature also lives.

Watch out: Older machine literature quotes GD², the "flywheel effect", which is four times the moment of inertia because it uses the diameter rather than the radius of gyration. A GD² figure divided by four gives the moment of inertia, and machines have been mis-sized by people who did not know to do it.

1 t·m² 1,000 kg·m²