Definition of tensile strength
Tensile strength is the critical value of the transition from uniform plastic deformation to local concentrated plastic deformation, and it is also the maximum load-bearing capacity of the metal under static tensile conditions. The tensile strength is the resistance to the maximum uniform plastic deformation of the material. Before the tensile sample is subjected to the maximum tensile stress, the deformation is uniform, but after it exceeds the limit, the metal begins to shrink, which results in concentrated deformation. For no (or Very small) brittle material with uniform plastic deformation, which reflects the material's resistance to fracture. The symbol is Rm (GB / T 228-1987 old national standard stipulates the tensile strength symbol is σb), and the unit is MPa.