Poisson's ratios (coefficients) − approximate (indicative) values
Materials	ν
Steels	0,25 ÷ 0,31
Cast iron	0,21 ÷ 0,27
Copper-tin alloys (Cu-Sn alloys)	0,32 ÷ 0,36
Poisson's ratio − the ratio of transverse strain to longitudinal strain under uniaxial stress.