The most tightly bound of the nuclei is ⁶²Ni, a case made convincingly by M. P. Fewell in an article in the American Journal of Physics. Though the championship of nuclear binding energy is often attributed to ⁵⁶Fe, it actually comes in a close third. The four most tightly bound nuclides are listed in the table below with a tabulation of the binding energy B divided by the mass number A. The curve adapted from Fewell shows those nuclides that are close to the peak.

Nuclide	B/A (keV/A)
^62Ni	8794.60 0.03
^58Fe	8792.23 0.03
^56Fe	8790.36 0.03
^60Ni	8780.79 0.03

Data from Wapstra and Bos.

(http://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin2.html#c2)