Metals • All metals belong to one of these two groups. • Ferrous metals are metals, which are mainly made of iron with small amounts of other metals or elements added in order to give the correct properties. Almost all ferrous metals are magnetic and can be picked up with a magnet. These metals rust or oxidise if not treated as they contain iron. • Non-Ferrous metals are those metals, which do not contain iron. These metals are not magnetic and cannot be attracted by a magnet. Examples of these are aluminium, copper, lead, zinc and tin. These metals do not oxidise as they do not contain iron. Pure metals and alloys • All metals fall into two categories. They can either be pure metals or alloys. • A pure metal consists of a single element, which means that it is a metal only having one type of atom in it. The most commonly used pure metals are aluminium, copper, iron, lead, zinc, tin, silver and gold. • An alloy is a mixture of two or more pure elements. Pure metals sometimes lack certain required properties. To create these properties a number of these pure metals are combined together. • Pure aluminium is rarely used because it is too soft. It is normally mixed with other metals, which produce aluminium alloys that are even stronger than mild steel, are resistant to corrosion but still retain the lightness of aluminium. Name the metals? • Mild steel. It is used for general structural work for example girders, nuts, bolts, screws, car body panels and non-cutting tools. • If mild steel is coated in tin it is called ‘Tin plate’. • If mild steel is coated in zinc it is called ‘Galvanised sheet’. • If mild steel is coated in lead it is called ‘Terne sheet’. Name the metals? • Aluminium. It is used to make car bodies, cooking utensils, engine cylinder heads, window frames, insulation, foil food wrapping and boats. Name the metal being poured? To give you a clue it is used to make window frames and aircraft. • It is mixed with copper to make an alloy. This alloy is much stronger than pure aluminium. • Duralumin is used to make parts of aircraft. Name the metals? Medium carbon steel. It is used to also make garden tools, axles and shafts. Name the metal used to make the rear sprocket on this bike? Name the metals? • High Carbon Steel. It is used to make hand tools, chisels and punches. It is also called tool steel. Name the metal used to make this centre punch? Material Type Uses Properties Mild steel Ferrous metal Nails, screws, nuts and bolts, girders, car bodies Tough, malleable, high tensile strength, easily joined, poor resistance to corrosion, general-purpose metal. Brass Nonferrous metal Ornaments, boat fittings, castings. Corrosion resistant, polishes well. Hard, easily joined, good conductor of heat and electricity. Copper Nonferrous metal Hot water storage cylinders, central heating pipes, electrical wires, copper clad electronics boards Good conductor of heat and electricity, corrosion resistant, easily joined, polishes well, solders and brazes well, expensive to buy. Stainless steel Alloy Sinks, cutlery, dishes, teapots Hard and tough, resists wear, corrosion resistant, difficult to cut and file. Aluminium Nonferrous metal Kitchen cooking utensils, pans, packaging, cans, window frames High strength to weight ratio, light, soft, difficult to join, good conductor of heat and electricity, corrosion-resistant, polishes well.