The tensile strength of the foot screws is the tensile strength of the round steel itself. The size is equal to the cross-sectional area and the design value of the tensile strength (140MPa) is the allowable tensile strength of the design. The ultimate tensile strength is to multiply the area of the section (which should be the effective area of the thread) times the tensile strength of the steel (Q235 tensile strength is 235MPa). Because the design value is safe, the resistance of the design is less than the limit resistance.
Tensile strength: also called strength limit refers to the maximum stress value of the material before pulling out. Allowable tensile strength: the maximum stress under the normal limit state. Nominal tensile strength: the individual should be from the nominal diameter of the understanding, is the average, and the licensed tensile strength is not the same!