Abstract Average Sherwood numbers based on experimental results were determined for a sublimating naphthalene cylinder subjected to a crossflow of air. The range of Reynolds numbers for all tested cylinders was from 4700 to 141 000. The nominal diameters of the tested cylinders were 25·4, 50·8 and 76·2 mm (i.e. 1, 2 and 3 inches respectively). The average uncertainty of the reported data was estimated to be ±9·7%. The experiments were performed using an open-loop wind tunnel. The test cylinders were cast using molten naphthalene and the test method involved naphthalene sublimation. The resultant expression is given in dimensionless form.