In the tensile test, the maximum reduction of the cross-sectional area at the reduced diameter and the percentage of the original cross-sectional area after the specimen is broken is called the section shrinkage. Expressed in ψ, in%. The formula is as follows: Where: S0 - the original cross-sectional area of the sample, mm2; S1 - the minimum cross-sectional area of the specimen after the breakage, mm2.