Bismuth – the new ecologically green metal for modern lubricating engineering

Bismuth is relatively little known in general; however, it has been known since the fifteenth century in Germany and was called by Paracelsus “Bismutum”. With very similar properties to lead, it could be called the “twin brother of lead”, but bismuth is considered non‐toxic and used in cosmetics and pharmaceuticals. It is really a unique metal, considered as a metal within the periodic table of elements, but has more similarity to semimetals than to metals. Bismuth replaces the formerly and widely used lead in EP‐greases and EP‐lubricants giving better properties to them, even using down to half of the metal concentration. Bismuth has very high synergism to sulphur, the oldest known element. So, the combination of the oldest known element sulphur with the newest “green and ecologically clean” metal Bismuth – is actually the modern and metallic extreme pressure technology – that follows the formerly used, during many decades, sulphur‐lead‐technology – but being non‐toxic.