The melting curves of indium and bismuth were determined in a piston‐cylinder device. A comparison of the results obtained by differential thermal analysis and volumetric techniques confirms the existence of an asymmetric friction component. Transition pressures are overestimated if allowance is not made for asymmetric friction. The application of Mirwald’s ’’zero friction’’ technique for talc and NaCl assemblies indicated that only symmetrical and not asymmetrical friction is eliminated.