Brass is the generic term for a range of copper alloys – made up of copper and zinc – with differing combinations of properties, including strength, machinability, ductility, wear-resistance, hardness, colour, antimicrobial, electrical and thermal conductivity, and corrosion resistance.
Brass alloy sets the standard by which the machinability of other materials is judged and is also available in a very wide variety of product forms and sizes to allow minimum machining to finished dimensions. Brass does not become brittle at low temperatures like mild steel.
Brass also has excellent thermal conductivity, making it a first choice for heat exchangers (radiators). Its electrical conductivity ranges from 23 to 44% that of pure copper.
Colours of Brass
Brasses have a range of attractive colours, ranging from red to yellow to gold to silver. With the addition of 1% manganese, brass will weather to a chocolate brown colour. Nickel silvers will polish to a brilliant silver colour. Brasses are easy to shape and, with all these colours available, it is not surprising that architects and designers have used brasses to enhance the appearance of new and refurbished buildings, both inside and out.
Brass and Hygiene
Copper and brass alloys are playing a leading role in the fight against hospital-acquired infections such as MRSA and Clostridium difficile. It has been shown that these pathogens, which can be spread by touch, will die in a few hours on a copper or brass surface. This does not happen on stainless steel or plastic.
The brass industry throughout the world is well organised and equipped to recycle copper alloy products at the end of their long lives and process scrap (swarf and offcuts). Making brass from new copper and zinc would be uneconomical and wasteful of raw materials so, since new brass articles are made from recycled scrap, brass is said to be sustainable. In the UK brass manufacturers use almost 100% brass scrap.