Main sequence eclipsing binaries taken from Torres et al. (2010) in which both components have masses in the range 1.6–2.4 M_⊙, and relative errors in the masses and radii of 3% or better. Primary and secondary components are connected with dotted lines, and stars that are confirmed or probable Am stars are marked with open circles. SW CMa and HW CMa are shown with filled symbols. The thick solid lines are drawn for reference, and correspond to solar-metallicity isochrones from the series of Yi et al. (2001) for ages of 50 Myr and 1 Gyr.