Lubricant Additives

COMLUBE Extreme Pressure Bismuth Additives are metallic soaps based on synthetic carboxylic acids. They are supplied in liquid form and are stable, highly soluble and carefully controlled to ensure that quality and specifications comply with corresponding data sheets. COMLUBE Extreme Pressure Additives are supplied in various concentrations depending an customer requirements.




A new metallic non-toxic replacement for lead as an extreme pressure additive in gear oils and greases.

Tests have been conducted which show that Bismuth Octoate has a much higher extreme pressure property in Gear Oils and Greases than the traditional Lead Naphthenate. This phenomenon is believed to be a result of the lower melting points of the Bismuth alloys formed during the high load, high temperature and sliding conditions in a typical Extreme Pressure application.

Bismuth compounds have been used in the pharmaceutical field because of its anti-septic properties for a long time. Bismuth oxycloride is used in cosmetics and Bismuth subcitrate is used in an antiacid preparation for the treatment of peptic ulcers in the stomach. These applications demonstrate Bismuths‘ non-toxicity.

Bismuth has a crystal structure similar to that of Antimony based on a rhombical space lattice. It is considered to be a metal, however, it has properties similar to semi-metals. Bismuth crystallizes with the coordination number 3 whereas metallic elements crystallize with coordination numbers of 8 or 12. This means that the atoms in the Bismuth crystal lattice are more flexible and the metal is more reactive. This can account for the good E.P. properties of Bismuth. When used in conjunction with sulphur compounds the resulting Bismuth Sulphide has a higher polarity than the Lead Sulphide which can also partially account for the improved E.P. properties. Bismuth organometal compounds are easily emulsifyable with water and hence can be used in soluble oils. Bismuth has mild antiseptic and bacteriostatic properties which can be used to introduce a bactericide component into the soluble oil.


MSDS available on request.


Product / Grade Metal Content Appearance Colour Solids Content Specific Gravity (at 25°C) Viscosity (at 25°C) Application information
  %m/m     %m/m   mPas  
Bismuth Octoate 28% White Spirits 27.5 - 28.5 Clear Liquid Orange - Yellow 82 - 88 1.1 - 1.4 1500 max Lead Replacement in lubricant additives
Bismuth Octoate 25% White Spirits 24.5 - 25.5 Clear Liquid Orange - Yellow 73 - 79 1.0 - 1.2 800 max Extreme Pressure grease additive
Bismuth Neodecanoate 20% White Spirits 19.5 - 20.5 Clear Liquid Orange - Yellow 70 - 85 1.05 - 1.25 1500 max. Lubrication additive
Bismuth Neodecanoate 20% Base Oil 19.5 - 20.5 Clear Liquid Orange - Yellow70 - 85 70 - 85 1.1 - 1.3 2000 max  Lubrication additive