RED BRASS AND SEMI-RED BRASS

Bronze foundry men have had more experience in handling alloys of this type than in any other single group of copper-base casting alloy, and foundry practice for these materials is fairly we!! understood.
Multiple gating is highly desirable to avoid turbulence and overheating of local portions of the mold. Risers should be p1aced where they have access to hot metal. Sprues should be small in diameter and should be kept filled during pouring. Molds should be effective1y vented.
With the semi-red brasses. the cast ability i5 somewhat better. The higher zinc content may present a smoke. and fume pmb1em in the foundry. although this is usually not serious. The greater amount of zinc in these alloys may also necessitate more careful skimming before pouring to avoid dross being poured .into the mold cavity with the metal.
Phosphor-c:opper deoxidizer should be used with these alloys to help control the gas content and to improve their cast ability. Under usual conditions, the recommended addition is two ounces per hundred pounds of metal.
This group of alloys may be the easiest of all for the non-ferrous foundry man to handle. Good foundry practice will enable any foundry to produce salable red brass and semi-red brass castings.