ESDU 68019 presents data based on the Blasius relations for skin friction and various thickness parameters for the case of the flat plate in incompressible flow. For the general case of the flat plate in compressible flow with heat transfer, data are given for the skin friction coefficients and momentum thickness, normalised with respect to the equivalent values for incompressible flow at the same Reynolds number. Also presented are shape parameter, and data for normalised boundary layer thickness. The application is extended to cover the two-dimensional supersonic flow about sharp wedges, the axisymmetric flow along cylinders and the axisymmetric supersonic flow about sharp-nosed cones by means of theoretical factors applied to the flat plate data. Discussions of the limitations of the methods used in the preparation of these data are given and their use is illustrated by two examples.