A rotating‐anvil shear press was used to measure the friction coefficient and shear strength of thin layers of copolymers of tetrafluoroethylene with ethylene and hexafluoropropylene at room temperature at pressures up to 5 kbar. The friction coefficient of both copolymers decreased monotonically, approaching a small asymptotic value at high pressure. The shear strength of both materials increased approximately linearly with pressure. The ethylene copolymer exhibited a small discontinuity suggestive of a polymorphic transformation.