Thermal contact conductance measurements were made on ground-lapped interfaces of tool steel and they were compared with the recently proposed elastoplastic model. The type of deformation associated with contact conductance measurements of ground-lapped interfaces of untreated tool steel was elastoplastic, whereas heat treated tool steel (HRC = 40 and 58) underwent fully elastic deformation. It is found that the interface equivalent elastic modulus for tool steel and some previous data are higher than the equivalent bulk elastic modulus. Even though the effect of sampling interval on the elastoplastic model is significant, a good comparison between previous data and the model is observed with surface slope obtained from a commercial surface analyser. Simple correlations for the elastoplastic model and a semi-explicit expression to calculate the dimensionless contact pressure are proposed.