Text version of the page

Swelling – Under the action of lubricants, vapours or gases,sealing materials made from rubber, elastomer, etc., can be negatively affected by swelling. Synthetic oils Tackifiers/Adhesion improvers – In contrast to mineral oils, these oils areproduced by chemical synthesis. Synthetic oils usually have a good viscosity/temperature behavior, low tendency to oxidize, low pour point, high temperature stability, and good chemical resistance. – Additives to oils andgreases to improve adhesion (e.g. polyisobutene). Thickeners – Thickeners usually are metal soaps (soap-thickened) but also organic or inorganic thickening agents (not soap-thickened as e.g. silica, bentone, urea, PTFE etc.). Tribology – Science of scientific research and technicalapplication of the relation between friction, wear and lubrication,including lubricants. Unworked penetration – The consistency of a grease orpaste in the state of rest, i.e. in the state of material as supplied. Viscosity – The viscosity of a liquid is a measurement of itsresistance to flow. Wear – Caused by friction and contact between contactingsurfaces after break-through of the lubricating film. Water resistance of a grease – The behavior of lubricatinggreases in the presence of water is of great importance for their applicability as anti-friction bearing greases. For this application, either a water-repellent (water resistant) or a water-absorbent (emulsifiable) lubricating grease is required. Weld load Worked penetration – The ability of a lubricant to absorb pressure,measured in kilogram (kg), the load at which the lubricating film breaks, during sliding of test specimens against each other, and at which both test specimens weld together. – Under mechanical shear, lubricatinggreases often change their consistency. Therefore, it is more reasonable to indicate the worked penetration. It is the consistency of a worked grease.

Molykote® Industrial Lubricants - 21122 Glossary of Terms

Scoring – Trench-shaped marks in metal, caused bymachining or by scuffing Salt-water spray test – The corrosion of steel is measuredunder the influence of saline fog. Sheet steel is coated with a lubricant and exposed to saline fog in a closed chamber. After the test, the number of hours are measured which have passed until a certain grade of corrosion was reached. Scuffing – Damage to material surface through inadequatesupply of lubricant, or as a result of overloading. The lubricating film is broken. Service temperature range – The range in which thelubricant meets requirements and an acceptable lubrication interval is achieved. Silicones – Polymers with good temperature and oxidationresistance. Also used as high and low temperature lubricants. Soap in lubricating grease Solid lubricants – Solid substances which are appliedbetween sliding surfaces to reduce friction and wear and prevent scoring, cold welding and galling. – Combination of a fatty acidand a metal hydroxide. Through the proper selection of the fatty acid and the metal hydroxide (calcium, lithium, aluminum) the properties of the soap can be changed as to water resistance and temperature resistance. Solvent – A liquid which will dissolve a material and yield ahomogeneous product. Specialty lubricants – Lubricants with particular properties/characteristics for special applications. Specific weight – See density Stick-slip – Stop-start relative movements of two slidingsurfaces, caused by the difference in coefficient of fric- tion between hydrodynamic and boundary lubrication. Suspension – A uniform dispersion of the fine particles of asolid in a liquid which does not dissolve them. 51