What Is Manganese Bronze?

Manganese bronze is a bronze alloy — a blend of different metals — that uses manganese for strength. While the alloy is called manganese bronze, very little manganese is used in the alloy, which is mostly made from copper and zinc. The copper and zinc blend technically makes it brass instead of bronze. This metal finds use in the industrial sector, and is used to make gears, nuts, bearings and valve stems. There are several ways to join this metal, but the best way is via coated-metal arc welding, which will provide the longest lasting joint.

Copper is used as a primary metal in creating many alloys, including bronze. Bronze is usually created mostly from copper and tin, but manganese bronze mostly uses copper and zinc. As the name suggests, manganese is added to the bronze alloy, but only a small percentage is used. From 2.5 percent to 5 percent of the entire alloy is manganese. Other metals found in this alloy in varying amounts include aluminum, iron, lead, nickel and tin.

Manganese is added to the bronze alloy for several reasons. Manganese is stronger than other bronzes, which makes it a tough metal that is great for industrial uses. Manganese also is a free element, meaning it has a very strong rust resistance that carries over to the products made from it. This bronze also is highly machinable, meaning it can easily be cut with machine tools to be shaped into parts or components.

Manganese bronze is not used in the commercial or consumer market; it is found almost exclusively in the industrial sector. This is because of the durability and toughness of manganese bronze. It is used to make bushings, valve stems, hydraulic cylinder components and propellers. Its primary use in industry means this bronze is typically sold in large amounts, with a standard length of 144 inches (3.66 meters).

Joining metals, either to make parts or to secure their installation, is important in the industrial sector. There are several ways to join manganese bronze, including soldering and brazing, but the most effective method is coated-metal arc welding. The electrode is covered in a flux, which disintegrates as it burns into the metal. This leaves slag that, while not attractive, offers extra protection and ensures the bronze will not dislodge after the welding.