What’s admiralty brass?


Brass is a Copper-zinc alloy with the addition of alloying elements such as Tin, Arsenic, Manganese, Aluminum, Silicon and Lead, which are usually less than 5 %. Theses addition elements enhance the whole alloy properties, making the material is ideal for specific application areas.

There are over 40 standard grades of brass with zinc content varying from around 5-40%. Admiralty brass is a version of Brass that contains 70% copper, 29% zinc and 1% tin. The solubility of tin in brass varies greatly. When the solubility of zinc in copper increases from zero to about 38%, the solubility of tin in alpha phase decreases from 15% to 0.7%. Tin is very insoluble in a Zn-saturated alpha solid solution, but when the zinc concentration increases to beta phase appearance, the tin solubility increases. A small amount of tin solid solution in brass can improve the strength and hardness of the alloy, but when the amount is more than 1-5%, the plasticity reduced. That is the addition of tin that makes it the distinction from other Brass Alloys.

The reason for the addition of tin is because of the added corrosion resistance in saltwater. Admiralty Brass has good corrosion resistance and is specially used for fresh, salt or brackish water application, and for that reason, it is also called the “admiralty bras”.

Admiralty brass is available in forms of sheet and tubing. Admiralty Brass tubes have good corrosion resistance and are specially used for steam condensers cooled with fresh, salt or brackish water. They are usually used as condenser tubes, Evaporator and Heat Exchanger tubes, Distiller tubing in oil refineries, heater equipment as well as other industrial processes.

There are three types of admiralty brass in American Society for Testing Material, that’s UNS C44300, C44400, C44500(previously used destination are type B, type C, type D in turn). Copper alloy UNS C44300, C44400, C44500 tubes shall be furnished in the annealed O61 temper unless otherwise specified on the purchase order. The copper elements of them various from 70% to-73%, while exist a tiny difference in the content of arsenic, antimony and phosphorus.


Copper alloy  Tin  Lead  Iron max Zinc Arsenic Antimony Phosphorus
C44300 0.9-1.2 0.07 0.06 remainder 0.02-0.06 / /
C44400 0.9-1.2 0.07 0.06 remainder / 0.02-0.1 /
C44500 0.9-1.2 0.07 0.06 remainder / / 0.02-0.1


Admiralty Brass is one of the most frequently used brass alloy in their family, mainly used in condenser and heat exchanger applications by the petrochemical industry, ship-building, power plants and desalination plants etc. More details about size, dimension and price, Contact us now.