The invention relates to a method of manufacturing a copper-nickel-silicon alloy with a composition Cu (balance), Ni 1.5-5.5%, Si 0.2-1.05, Fe 0-0.5% and Mg 0-0.1% (all in percent by weight), and use of the alloy for pressure-englazable casings. The method permits an alloy with a very high elastic limit with very good conductivity and good cold reformability and differs from the conventional method of manufacturing such alloys by heating to about 950.degree. C. and fairly rapid cooling after a preceding cold rolling operation. An improvement in the properties can be achieved by ageing of the alloy at 300.degree. C. to 600.degree. C. for several hours.

A copper-zinc alloy for semi-finished products and articles which are highly loaded and subjected to extreme wear especially synchronizing rings. The alloy possesses a composition of 40 to 65% Cu, 8 to 25% Ni, 2.5 to 5% Si, 0 to 3% Al, 0 to 3% Fe, 0 to 2% Mn and 0 to 2% Pb, with the balance being zinc and unavoidable impurities. The Ni:Si ratio is about 3 to 5:1, and the structure consists of at least 75% .beta.-phase, with the balance .alpha.-phase, in the absence of a .gamma.-phase. Nickel silicides occur predominantly as a round intermetallic phase. The alloy provides quite substantially higher levels of resistance to wear.