mm³

cubic millimeter

VolumeSection modulusexact by definition

The cubic millimetre is 10⁻⁹ cubic metres, exactly one microlitre. It is the unit of small machined volumes and of material removal rates in cutting, and it is the classical unit of blood cell counts, where "per mm³" and "per μL" are the same denominator.

1 mm³ (Volume)0.000001 L
1 mm³ (Section modulus)1 mm³
As a unit of section modulus

The cubic millimetre is exactly 10⁻⁹ cubic metres, an exact relation. It pairs naturally with stresses in N/mm², since a moment in newton millimetres divided by a section modulus in mm³ gives a stress in N/mm², which is exactly megapascals with no conversion needed.