Masses ofCo m have been experimentally determined for the first time and found to be more bound than predicted by extrapolations. The isobaric multiplet mass equation for the T = 2 quintet at A = 52 has been studied employing the new mass values. No significant breakdown (beyond the 3σ level) of the quadratic form of the IMME was observed (χ 2 /n = 2.4). The cubic coefficient was 6.0(32) keV (χ 2 /n = 1.1). The excitation energies for the isomer and the T = 2 isobaric analogue state in 52 Co have been determined to be 374(13) keV and 2922(13) keV, respectively. The Q value for the proton decay from the 19/2 − isomer in 53 Co has been determined with an unprecedented precision, Qp = 1558.8(17) keV. The proton separation energies of 52 Co and 53 Ni relevant for the astrophysical rapid proton capture process have been experimentally determined for the first time.