Dating antique brass
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 8.4 to 8.73 g/cm³ (approximately .303 lb/cubic inch).
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.
The general softness of brass means that it can often be machined without the use of cutting fluid, though there are exceptions to this.) to be formed on the surface that is thin, transparent and self-healing.Brass has been used for decorative pieces and useful tablewares since ancient times. C., when the Roman empire existed, brass was used across Europe. Additional brass items may be found under Bell, Candlestick, Tool, or Trivet. However, bronze and brass may also include small proportions of a range of other elements including arsenic, phosphorus, aluminium, manganese, and silicon.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.