A packaging sheet metal product from a cold-rolled steel sheet with a thickness of less than 0.6 mm has a specified composition. The packaging sheet metal product during biaxial deformation in a bulge test has a lower yield strength (SbeL) of more than 300 MPa and a corresponding elongation at break (Ab) of more than 10 % and in the plastic region between the Lüders elongation (Abe) and an upper (plastic) elongation limit of εmax=0.5·Ab(SbeL/Sbm) has a biaxial stress/strain diagram σB(ε) that can be represented by a function εmax=b·εn, with: σB is the true biaxial stress in MPa; ε is the amount of true elongation in the thickness direction in %; Sbm is the absolute strength; b is a proportionality factor; and n is a strain-hardening exponent. A strengthening of the packaging sheet product in the thickness direction is characterized by a strain-hardening exponent of n≥0.353−5.1·SbeL/104 MPa.