Due to the weak intermolecular forces the silicones themselves are not, in general, strong lubricants in high-load-bearing applications.
In these applications they are most commonly used together with additives to enhance the load bearing properties. On the other hand the silicones have the ability to function over a wide temperature range. Phenyl-containing silicone fluids show greater temperature stability and lower compressibility in comparison to their pure methyl counterparts. They find uses in the lubrication of low-load bearing applications for critical devices such as timers and systems involving rubber, plastic and aluminum mating surfaces. Various silicones containing long-chain alkyl groups are useful as lubricants with enhanced properties over those of the dimethyl fluids. Fluorosilicones show an extremely wide temperature range and strong chemical resistance with applications as aerospace lubricants, precision timing devices and electrical contacts. In addition fluorosilicone greases can be formulated with fluoropolymer thickeners into greases for extreme pressure applications.