Buying and Selling Brass Scrap
Brass Scrap will be brought in 2 categories:
- Mixed Brass (Clean): Clean Brass with no attachments such as steel, plastic, rubber and must be free of oil and grease.
- Coast Brass (Dirty): Brass is allowed to have 15% – 20% contamination i.e. steel. But must be free of oil and grease.
Mixed Brass (Clean)
Shall consist of mixed yellow brass solids including brass castings, rolled brass, rod brass, tubing and miscellaneous yellow brasses, including plated brass. Must be free of manganese-bronze, aluminum-bronze, unsweated radiators or radiator parts, iron and excessively dirty and corroded materials. Must also be free of any type of munitions including, but not limited to, bullet castings.
Coast Brass (Dirty)
Will contain predominately honey brass and other red brasses typically sold as 85% clean.
Typically under 300mm x 300mm in size, free of oil and grease. To be sold as being suitable for melt scrap without processing.
Shall consist of the cuttings of new unleaded yellow brass sheet or plate, to be clean and free from foreign substances and not to contain more than 10% of clean brass punching under ¼ inch. To be free of Muntz metal and naval brass.
Shall consist of strictly rod turnings, free of aluminum, manganese, composition, Tobin and Muntz metal turnings ; not to contain over 3% free iron, oil or other moisture ; to be free of grindings and babbitts ; to contain not more than 0.30% tin and not more than 0.15% alloyed iron.
Mixed Unsweated Auto Radiators
Shall consist of mixed automobile radiators, to be free of aluminum radiators and iron-finned radiators. All radiators to be subject to deduction of actual iron. The tonnage specification should cover the gross weight of the radiators unless otherwise specified.
Brass History and Uses
Brass is a metal alloy made of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties. It is a substitutionally alloy: atoms of the two constituents may replace each other within the same crystal structure.
By comparison, bronze is principally an alloy of copper and tin. However, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon. The term is also applied to a variety of brasses, and the distinction is largely historical. Modern practice in museums and archaeology increasingly avoids both terms for historical objects in favour of the all-embracing “copper alloy”.
Brass is used for decoration for its bright gold-like appearance; for applications where low friction is required such as locks, gears, bearings, doorknobs, ammunition casings and valves; for plumbing and electrical applications; and extensively in brass musical instruments such as horns and bells where a combination of high workability (historically with hand tools) and durability is desired. It is also used in zippers. Brass is often used in situations in which it is important that sparks not be struck, such as in fittings and tools used near flammable or explosive materials.
Brass has higher malleability than bronze or zinc. The relatively low melting point of brass (900 to 940 °C, 1652 to 1724 °F, depending on composition) and its flow characteristics make it a relatively easy material to cast. By varying the proportions of copper and zinc, the properties of the brass can be changed, allowing hard and soft brasses. The density of brass is approximately .303 lb/cubic inch, 8.4 to 8.73 grams per cubic centimetre.
Today, almost 90% of all brass alloys are recycled. Because brass is not ferromagnetic, it can be separated from ferrous scrap by passing the scrap near a powerful magnet. Brass scrap is collected and transported to the foundry where it is melted and recast into billets. Billets are heated and extruded into the desired form and size.
Aluminium makes brass stronger and more corrosion-resistant. Aluminium also causes a highly beneficial hard layer of aluminium oxide (Al2O3) to be formed on the surface that is thin, transparent and self-healing. Tin has a similar effect and finds its use especially in seawater applications (naval brasses). Combinations of iron, aluminium, silicon and manganese make brass wear and tear resistant.
To enhance the machinability of brass, lead is often added in concentrations of around 2%. Since lead has a lower melting point than the other constituents of the brass, it tends to migrate towards the grain boundaries in the form of globules as it cools from casting. The pattern the globules form on the surface of the brass increases the available lead surface area which in turn affects the degree of leaching. In addition, cutting operations can smear the lead globules over the surface. These effects can lead to significant lead leaching from brasses of comparatively low lead content.
Silicon is an alternative to lead; however, when silicon is used in a brass alloy, the scrap must never be mixed with leaded brass scrap because of contamination and safety problems.
Brass can be found around the house in the forms of:
- Shower Heads
- Water Meters
- Shells (Bullets)