1. In Ni−Be spring alloys alloyed with Mo, Mo+B, W, and V the resistance to small plastic deformation increases. 2. The strengthening of Ni−Be alloys containing Mo, W, or V is due to the precipitation of a greater number of particles of the β'-phase because of the decrease in the solubility of Be in the nickel solid solution. The addition of Co has the same effect and this leads to a decrease of the resistivity of the alloys as compared to that of the Ni−Be alloy. 3. Alloying of Ni−Be alloys with Mo and B or W and V increases the heat resistance of the alloys.