Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange colour. Copper turns green because of an oxidation reaction; that is, it loses electrons when it's exposed to water and air. The resulting copper oxide is a dull green.

Titanium is a lustrous transition metal with a silver colour, low density, and high strength. Titanium is resistant to corrosion in sea water, aqua regia, and chlorine. Titanium was first discovered in 1791 in Menachan Valley, Cornwall, England, by clergyman and amateur chemist William Gregor.

Steel is an alloy of iron and carbon and other elements. Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Iron is the base metal of steel.

In metallurgy, stainless steel, also known as inox steel or inox from French inoxydable, is a steel alloy with a minimum of 10.5% chromium content by mass. Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. There are over 150 grades of stainless steel, of which fifteen are most common.

Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels.

Brass is an alloy of copper and zinc, in proportions which can be varied to achieve varying mechanical and electrical properties. It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure. In contrast, bronze is an alloy of copper and tin.