August 2021 Volume 3

EQUIPMENT & TECHNOLOGY

The Evolution of Brass Forging By Mike Hoff aka “Mr. Brass”

Today’s presses employ in-press billet size and weight control, with a series of side cores to reduce forging weight, the need for secondary trimming, no reprocessing of flash, reduced post-forge machining due to near net sizing, and the ability to process lead-free alloys. We know that a forging has many advantages over a casting, but principle among them is the inherent porosity found in castings that result in occasional leakage and vessel failure under pressure. This requires that all casting be pressure tested prior to assembly and the fallout can be significant. Forgings have no porosity issues. This allows for leak testing to be performed on the finished assembly as opposed to the raw part. This is particularly beneficial in high brass content high-volume assemblies, like ball valves. Today’s high-tech presses are turnkey systems with all necessary components integral to the press. This is referred to as “foundry in a box”. The furnace, bar cutting, and press are an all-in-one design that requires minimal foundation and only a requirement of basic utilities brought to the system. The system can be run in a three- car garage and does not require an existing foundry, or extensive foundry infrastructure. The old traditional brass forging line required a minimum of five machines, twelve steps, six transports and three operators.

The European market, especially in Italy, has embraced hot brass forging for centuries while the North American market has traditionally relied upon brass production from bar, shaped bar, and green sand castings. Today, the tide is turning as near net shape forging options for light metals has progressed significantly. In addition, environmental concerns surrounding green sand foundries has sent traditional producers toMexico, or to sourcing fromChina. Producers, especially OEMs, that want to keep production in house, have now turned to forging as their European counterparts have for some time. Long gone are the days when brass forgings resembling a pancake of some kind.

8

FIA MAGAZINE | AUGUST 2021