What is an "alloy"?
   An alloy is a mixture of metals melted together to produce another metal with distinct characteristics different from the metals from which it is made.

   What is a "copper alloy"?
   A copper alloy is an alloy of primarily copper, mixed with different alloying elements that give rise to an entire range of materials, each of which is designed to maximize a particular characteristic such as strength, ductility, formability, machinability, or electrical conductivity. These alloys are grouped into "families", the names of which have become familiar - coppers, brasses, bronzes, copper-nickels, and nickel-silvers.
   Coppers are made from copper with trace elements
   Brasses are made from copper alloyed primarily with zinc
   Bronzes are made from copper alloyed primarily with tin
   Copper-Nickels are made from copper alloyed primarily with nickel and manganese
   Nickel Silvers are made from copper alloyed primarily with nickel and zinc

   What is a "wrought copper alloy"?
   "Wrought" means the metal was solid and squashed into its final shape - sheets, plates, bars, tubing, angles, channels, etc.
    What is a "cast copper alloy"?
   "Cast" means the metal was melted and poured into its final shape - faucets, knobs, handles, grates, sculptures, etc.
    Which One?
   Throughout this website we deal only with wrought alloys. We have not extended the alloy color and product classification presented here to the cast copper alloys. However, the Copper Development Association, responsible for the existing organization of information and nomenclature surrounding copper alloys in the USA, has developed a similar classification for cast alloys. Although there is no color information for cast alloys, there is a great deal of technical information about them.
   Until we do for cast what we've done for wrought, my only suggestion for working with copper alloy castings on the job is to get your castings done early! Then get a piece of the cast material to your fabricator as soon as possible and have them sand it and lacquer it. Now you have a color sample of the actual cast metal you will be forced to accept on the project, and you can match that metal finish up to all of the stock metals  represented in this website, giving you the full set of stock wrought copper alloy alternatives that you can use on the job with your castings.

  Why so many? And why the odd collection of forms, different for each alloy?
   Because of their physical nature, each of the 40 copper alloys commonly available in the USA is produced only in a restricted set of shapes specific to that alloy. You will not be able to specify every shape of bar sheet or tube in every alloy. This means that in designing most projects using copper alloys the architectural metal designer will be forced to use more than one alloy - one for tubing, another for sheet, another for bar, and yet another for channel.
   Unlike the other "forms" pages in this website, I do not include actual images of the forms themselves, because there are so many among the whole group of 40 alloys. However, the finish, the sharpness of the edges, etc. of each form is consistent among all 40 of the alloys, and only the color is different among them.

Metal Color	+	the Metal Form	+	the UNS ID number	+	the Generic Name
				C26000		Cartridge Brass

Color and Shape
   Choose your alloy color, yes, BUT......
   Because of their physical nature, each alloy is produced only in a restricted set of shapes specific to that alloy. You will not be able to specify every shape of bar sheet or tube in every alloy. This means that in designing most projects using copper alloys the architectural metal designer will be forced to use more than one alloy - one for tubing, another for sheet, another for bar, and yet another for channel.
   The three alloys shown below are very common.
If you order sheet without specifying the alloy, you will receive alloy C26000 Cartridge Brass.
If you order tubing without specifying the alloy, you will receive alloy C27000 Yellow Brass.
If you order angles or channels without specifying the alloy, you will receive alloy C38500 Architectural Bronze.

These are images  of the actual metal.   Forms in which the alloy is regularly available UNS ID number Name of the alloy C26000  Cartridge Brass C27000  Yellow Brass C38500  Architectural Bronze

Each of these three alloys is regularly produced in the USA only in the set of shapes shown. But they are very different in color, and they all have a very different reaction to patina processes. If you are specifying "brass" sheet, tubing, and channel all in the same project, the finished product can end up with a surprising range of color differences.     Before specifying these alloys it is necessary that you know which alloys are produced in which shapes, and their relative color, perhaps choosing the same form in another alloy with a more acceptable color.