The hydromechanical response of a Wyoming-type bentonite (MX-80) and its interface with steel was studied in terms of shear resistance under different hydration levels. A series of shear tests under constant normal stress were performed in total suction controlled conditions. In the case of bentonite samples, higher shear resistance was obtained for higher levels of applied suction. The shear properties of the bentonite/steel interface were overall lower than the internal properties of the bentonite, and they were not affected in a significant way by the hydration level. All samples presented a compactive response during shearing.