What Is The Composition Of Brass?


The alloy brass is thousands of years old; it is a rather simple material, composed of copper and zinc. Depending on the percentage of the base materials, copper and zinc, plus other alloys, the result is a brass which has many uses. Brass can be used as for the manufacture of decorative accents for the home, bullet casings, musical instruments and hundreds of other products that relay on the unique qualities of the material. Generally brass is the color of butter but depending on the alloy mix, the color can vary; brass which has a high percentage of zinc is lighter than that which has a higher percentage of copper.

In some circles brass is spoken of as “cartridge brass” and “Dutch brass.” In the US brass is defined with a numerical code. 360 brass rod for example is actually defined as C360, with C being the designation for copper. The C is followed by digits that define the alloy content of the brass. In the system, any brass that starts with a number between one to seven it designates that the brass can be machined or forged; numbers eight and nine mean the brass can only be manipulated through casting. 360 brass rod is the norm for free machining brass, the composition is 61.5% copper and 35.5% zinc with minor traces of iron and lead.

The basic standard for brass is 67% copper and 33% zinc so you can see minor variances between standard brass and what is known in the industry as free machining brass. Brass is more durable and stronger than copper alone but does fall short of the strength of steel. In the case of 360 brass rod, iron has been added to make it harder and lead adds to its corrosion resistance.

Although the metal often contains alloys that fight corrosion, brass is usually finished in lacquer to provide maximum corrosion protection; when the home contains ornamental pieces which are made from brass, this fact needs to be considered as the lacquer is not intended to be removed. Manufactures will always recommend that brass be cleaned with a specialized polish which is non-abrasive. In the event the piece is a raw brass it is recommended that it should be cleaned with spirits and then given a light coating of olive oil. In the event the piece does tarnish, the best cleaner is vinegar.