Ageing resistance: The resistance against ageing which might occur
due to oxidation, overheating, the presence of certain metals like copper
and lead, light etc. The resistance to ageing can be improved by certain
additives (e.g. antioxidants).
Binder: An alternative term for non-volatile medium or vehicle and
refers to the material which forms the varnish film and which in a bonded
coating binds the particles of solids (solid lubricants) together.
Bleed: The separation of a liquid lubricant from a grease.
Boundary Lubrication: A state of lubrication in which the bearing
surfaces are not completely separated by a film of lubricant.
Co-efficient of Friction: Ratio of frictional force between two
surfaces sliding across one another to the force that is perpendicular to
Complex Grease: Grease thickened with a combination of a soap of a
long chain and a salt of a short chain organic acid.
Consistency: The hardness of a lubricating grease, also plasticity,
ductility, elasticity. It is the capability of a grease to resist a
Density: The density is the mass of a substance in grams in
relation to its volume in cm3.
Density = Mass / Volume = (Grams) / cm3
e.g. the density 0.900 g/cm3 means that 1000 cm3 (1 Litre) of this oil
weighs 900 grams.
DN-Value: The measure of the bearing speed; the average diameter of
a bearing (D) in mm multiplied by the rotations (N) per minute.
Drop Point: The dropping point of a grease is that temperature at
which grease passes from a semi-solid to a liquid state. It is a qualitive
indication of the heat resistance of a grease. The dropping point
temperature is determined when the first drop of grease falls through the
hole in the bottom of a cup during temperature increase.
Flash Point: The flash point is the lowest temperature at which
inflammable vapours are formed on the surface of the oil being tested
which will ignite in the presence of a flame.
Fretting Corrosion: Frictional wear which results from oscillations
with very low amplitude and high frequency. Usually the very small iron
wear particles react with oxygen to rust which finally results in seizing.
Another aspect of fretting corrosion is the rapid fatigue of the steel, a
fact which can easily lead to breaking. (Fretting corrosion can most
effectively be prevented by the separation of both metals partners, e.g.
by means of solid lubricants).
Friction: Resistance against sliding of two surfaces against one
Graphite: A type of elemental carbon. It has lubricating properties
either by itself or as a component in lubricants.
Grease: A solid to semi-fluid product of a dispersion of a
thickening agent in a liquid lubricant. Other ingredients imparting
special properties may be included.
Hydrodynamic Lubrication: The state of lubrication in which the
bearing surfaces are completely separated by a film of lubricant, thus
preventing contact between the surfaces.
Inhibitor: An additive used to control some undesirable
characteristics in greases, oils or fuels.
Load Carrying Capacity: A measure of the relative ability of a
lubricant to prevent wear under applied loads.
Lubricant: Medium to reduce the friction between two surfaces
sliding against one another.
Molybdenum Disulphide (MoS2): Often abbreviated as MOLY. A black,
lustrous powder that has a very low co-efficient of friction and serves as
a dry film lubricant in certain high temperatures and high vacuum
Oxidation resistance: The resistance of hydrocarbons in a lubricant
to react with oxygen.
Penetration: The measure which indicates the softness or hardness
of a grease. The depth of penetration of a standardized cone in a grease
sample is measured. (The higher the penetration, the softer the grease).
Silicones: Synthetic polymer with good temperature and oxidation
resistance. Also used as base oils for high and low temperature specialty
Solid Lubricants: Solid substances which are applied between
sliding surfaces to reduce friction and wear and prevent scoring.
Suspension: A uniform dispersion of the fine particles of a solid
in a liquid which does not dissolve them.
Synthetic Oils: Synthesized oil in contrast to mineral oils.
Synthetic oils usually have a good viscosity - temperature behaviour, low
tendency to carbonize, low freezing point, high temperature stability and
good chemical resistance.
Thickener: Thickeners usually are metal soaps (soap thickened) but
can also be organic or inorganic thickening agents (not soap thickened
such as silica, bentone, urea, PTFE, etc).
Tribology: The science of scientific research and technical
application of the relation between friction, wear and lubrication,
including the use of lubricants.
Viscosity: A measure of the thickness of a fluid.
Worked Penetration: Under mechanical shear lubricating greases
often change their consistency. Therefore it is more reasonable to
indicate the worked penetration. The worked penetration is the consistency
of a worked grease.
||FAQ and Glossary:
Here are the terms generally used with the lubricants, oils and
To be used in conjunction with the data sheets and MSDS (COSHH).
Throughout this website we endeavour to speak in straight talking
non-gobbledygook this will help should we require to use the