Brasses are alloys of copper and zinc (generally 5 to 40%), and may contain small amounts of other alloying elements.They fall into two classes: the alpha alloys with less than 37% zinc which are ductile and can be cold worked, and the alpha/beta or duplex alloys which are harder and stronger with limited cold ductility.
Alloys containing up to approximately 35% zinc are single phase alloys, consisting of a solid solution of zinc and alpha copper. These brasses have good strength and ductility, and are easily cold worked. The strength and ductility of these alloys increases with increasing zinc content. The alpha alloys can be differentiated by a gradual change in color, from golden yellow to red, as the zinc content is increased up to 35%. Gilding 95%, Commercial Bronze, Jewelry Bronze, Red Brass and Cartridge Brass are in this category of brasses.