Brass Fittings: Sand-Cast on a Core, Then Tapped

Couplings, elbows, tees and nipples for pipes are cast in brass around a sand core that forms the bore, then threaded. Turn a wooden pattern with core prints at the ends, bake oil-bonded sand cores, cast in green sand, and tap or die-cut the threads. The picture: a wooden core box with its sand cores (left), and the pattern with the finished casting (right).