Results. Most of the systems are composed of significantly unequal components, with mass ratios as low as similar to 0.5. We derived precise masses, radii, and surface temperatures for them, along with their metallicities. The average precision of mass and radii determinations is 0.3% and 1.4%, respectively, for the surface temperature. The spectroscopic and photometric temperatures of the components are usually consistent to within 100 K, but in some systems, the difference is much larger. The components of HD 149946 show the highest difference (up to 400 K), while the atmospheric models favour different surface metallicities. We also provide an updated calibration of the equivalent width of the interstellar sodium D1 line and the reddening E(B-V).