The friction factors and mass transfer coefficients in a tube with fins of e/D = 0.1, 0.2, 0.24 and 0.3 are investigated both experimentally and theoretically in the wide range of Reynolds numbers up to 8000. As expected the friction factor decreased linearly with Reynolds number up to Re = 200 and remained nearly constant at Re > 500 for all cases of e/D. The distribution of pressure between the fins is measured in detail. The perforated fins are proved to be effective both in reducing loss and in enhancing mass transfer.