Abstract The mechanical properties of sintered cupronickel (75wt.%Cu–25wt.%Ni) coinage alloy were studied as a function of briquetting pressure, sintering temperature and sintering time. The mechanical properties were established by using an MTS tensile apparatus. The sintered alloy was examined using scanning electron microscopy. The residual stresses of the sintered tensile specimens were evaluated by X-ray diffraction. It was found that the double-pressing and re-sintering process at 1120°C for 30 min results in an elongation of up to 45%, which is almost the same as or even higher than those of the normal cast and rolled material. A density of about 98% of the theoretical density was observed after coining. This behaviour is not dependent on the powder grain size or the first-sintering-cycle parameters, such as the compacting pressure, the sintering temperature (1050–1120°C) and the sintering time (15–30 min). It is suggested that as a result of the internal stresses existing after the re-pressing operation the product properties obtained are controlled by a strain-activated enhanced diffusion process.