The secular change after cold-working and anneal-hardening of 70/30 brass was measured by the hardness and the spring test. An increase in hardness and a decrease in bending deflection were observed at room temperature after cold-working, especially in high reduction specimens. As in the previous work on 60/40 brass, the change after anneal-hardening of 70/30 brass was influenced by the length of time from final cold-rolling to heat-treatment, and by the heating time of anneal-hardening. In general, the longer the times, the less the change. Heat-treatment was carried out at 200℃ for 15 min～3 hrs after the speciments had been allowed to remain at 40℃ for various durations following the final cold-rolling
