Abstract We produced submicrocrystalline Cu using the equal channel angular pressing technique with four passes. The as-deformed samples exhibited a high yield strength > 400 MPa and a poor elongation before failure < 20%. The majority of the grain boundaries after equal channel angular pressing were of the low-angle type. A series of heat treatments in the temperature range 220–300°C was performed and partly recrystallized microstructures with different fractions of recrystallized grains were obtained. The microstructures were analyzed by a combination of transmission electron microscopy, orientation image microscopy, light microscopy and scanning probe microscopy. The increase in ductility in partly recrystallized samples was accompanied by a decrease in the yield strength. It was suggested that to obtain a bulk nanocrystalline material which is both strong and ductile the majority of the grain boundaries should be of the high-angle type. It is shown that the scanning probe microscopy technique allows o...