Lead is a chemical element belonging to the carbon group. Its symbol is Pb and it has an atomic number of 82. Lead is a post-transition metal in the periodic table and is characterised by a blue/white colour when freshly cut, that gradually tarnishes to a duller grey with air exposure. In its liquid form, the metal has a shiny, silver-chrome colour.
Characteristic properties of lead include high density, malleability, ductility and rather poor electrical conductivity in comparison to other metals. It is very resistant to corrosion and can be alloyed to other metals easily, resulting in a significant change in its properties. For example, small amounts of antimony or copper can be added to lead to increase hardness and improve resistance to corrosion by sulfuric acid.
There are many uses for lead including construction, batteries, bullets, and nuclear radiation shielding. In the construction industry lead is used in roofing, cladding, flashing and gutters, as well as in decorative moldings to fix lead sheets. It is also used to make glazing bars for stained glass windows, although this is a practice that has become less common than it once was.
Lead is a key component in lead-acid batteries, which are the oldest type of rechargeable batteries. Compared to newer technologies they are relatively inexpensive and still widely used with 40-45% of batteries sold worldwide representing lead-acid batteries. Their main uses are in automobiles, lighting and ignition, as well as backup power supplies for alarm and small computer systems.
Lead is highly poisonous and can be hazardous to human health if ingested, whether that is inhaled or swallowed. Long term exposure can affect the nervous system and can cause nephropathy, weakness in the fingers, wrists and ankles, increase in blood pressure and brain damage. During the 20th Century, the use of lead in paints was dramatically reduced due to fears of lead poisoning and by the mid-1980’s lead use was heavily curtailed in most things other than battery products. White lead paint is no longer sold in industrialised counties and old paint should never be stripped by sanding as the dust is very dangerous if inhaled. Lead poisoning has been documented as far back as ancient Rome, with some having attributed the dementia of many Roman emperors to its use as a sweetener in wine.
Lead is sold by William Rowland in the form of full ingots which can be cropped to customer requirements, as well as sheets, shots, powder and wire.