Extra ingredient in lubricants, corrosion protection products and maintenance products used to achieve specific product properties.
Chemical modification over time of substances in use due to the effects of heat, light and oxygen.
Refers to a substance that can be decomposed by micro-organisms.
The ratio of release torque to tightening torque. For high-temperature screw pastes, this value is determined after tightening an M10 or M12 bolt (material: A2-70) using a torque of 40Nm or 70Nm and exposing it to a temperature of between +200C and +650C over a period of 100 hours.
As defined in DIN 51517, Part 1: designation indicating that a substance is suitable for use as a lubricating oil.
As defined in DIN 51517, Part 2: designation indicating that a substance is suitable for use as a circulating oil (C-oil + corrosion protection additive).
The aim of this standard is to ensure consistent designation of standard lubricants using a system of markings consisting of code letters and simple graphical symbols. The marking identifies characteristics including: type of lubricant, viscosity, consistency and operating temperature. Speciality Lubricants can only be described partially using DIN 51502.
The DN value, or speed index, is an empirical standard value that indicates the permissible maximum rotational speed at which grease can be used in a roller bearing. The DN value is essentially based on the pitch circle diameter (D+d)/2, but is also heavily dependent on the type of bearing/bearing assembly in question.
This is provided by solid lubricants under conditions of starved lubrication where there is insufficient lubricating grease or oil.
Lubricants with "Extreme Pressure" additives, designed to improve resistance to pressure and wear protection properties.
Food and Drug Administration - the national authority responsible for foodstuffs and pharmaceuticals in the United States.
The flash point is a measurement quantity applied to a flammable liquid that allows the level of fire hazard to be assessed. Depending on the type of product and the value of the flash point, the most common measurement methods are closed tester (defined in DIN 51755) and open cup (defined in DIN ISO 2592).
Fretting occurs when the lubrication film is broken, causing surface roughness peaks to weld together.
Coefficient of friction.
The FZG gear test rig is used to examine oils and greases specifically with regard to their suitability as lubricants in enclosed gears. The wear is determined for each level of load, with the result being given by what is known as the "scuffing load stage". The test method is described in DIN 51 354.
As defined in DIN 51524, Part 1: designation indicating that a substance is suitable for use as a hydraulic oil.
All metals with density > 5g/cm3.
Often referred to as HT lubricant, this is suitable for continous use at temperatures above +140°C.
DIN 51524, Part 2: designation indicating that a substance is suitable for use as a standard hydraulic oil (H-oil + corrosion protection additive).
DIN 51524, Part 3: designation indicating that a substance is suitable for use as a high performance hydraulic oil (HL-oil + EP additives).
This refers to situations where sliding partners are completely separated from each other by a liquid lubricting film.
International Standardization Organisation.
Guideline for organic materials in contact with drinking water (in Germany).
Landesgewerbeanstalt Nürnberg (State Trade Institute in Nuremberg) including the Institute für Lebensmitteltechnik (Institute of Food Chemistry).
A lubricant that is suitable for continuous use at temperatures below -20C.
This is a type of test rig used to measure the friction coefficient, wear and operating temperature for a lubricant with different materials under varying loads and at different sliding speeds.
Lubrication condition in which partial dry friction occurs at the same time as hydrodynamic lubrication.
Mox-Active (OKS registered trademark) is an additive used in lubricants to facilitate levelling of otherwise rough metal surfaces at the lubrication points, thereby producing a highly effective tribological surface finish. This means that run-in times are much shorter and friction and wear are considerably reduced.
Chemical formula for molybdenum disulfide (mineral molybdenite).
Mineral Oil Saturated Hydrocarbons / Mineral Oil Aromatic Hydrocarbons
Mineral oil hydrocarbons, which are absorbed by the body from contaminated food (e.g. through packaging material) and are suspected to cause health damage.
National Lubricating Grease Institute (USA).
The National Sanitation Foundation issues NSF registration numbers for lubricants that have a composition in accordance with the positive list of substances from the United States Food and Drug Administration (FDA). The classification H1 indicates a lubricant that may be used in situations where it is technically impossible to exclude the possibility of contact with foodstuffs. The classification H2 indicates a lubricant that may be used in situations where there is technical means by which it could come into contact with foodstuffs.
Oil separation is measured in weight percent, as defined in DIN 51817, with the lubricating grease under test being exposed to pressure and heat.
Measurement quantity used to determine the consistency of lubricating greases.
The pour point of an oil is measured as defined in DIN ISO 3016. This point lies a few degrees Celsius below the recommended minimum application temperature.
This test provides information on the behaviour and level of adhesion of solid lubricants under very high pressure and at low sliding speed. The test involves measuring the coefficient of friction, µ, and determining whether stick-slip occurs. Both results are important with relation to assembly operations (e.g. press-fit assembly) and for slide bars and guides (e.g. machine tools).
Room Temperature; as defined in DIN 50014 = +23C at 50% relative humidity.
This is the process of thickening a base oil to turn it into a lubricating grease by means of a reaction between metal hydroxides (Li, Ca, Al, Ba) and acids (preferably fatty acids).
These oils are produced using synthesising techniques. They have particularly good viscosity-temperature properties, are stable at low and high temperatures and are resistant to aging. Excellent separating properties. Outstanding lubricant for plastics and elastomers. Names such as polydimethylsiloxane or polyphenylmethylsiloxane describe the special structure of the molecular groups.
This is a method that is used to measure the corrosion protection properties of lubricants for rolling-bearings. This is achieved by adding water to the grease, which is then tested for corrosion over a defined period using self-aligning ball bearings run at a fixed speed and held at rest for specific periods of time, as defined in DIN 51802. If there is no visible corrosion of the test rings then the degree of corrosion is rated 0. The maximum rating is 5, which indicates very heavy corrosion.
A liquid that can dissolve other materials without chemically altering them.
This occurs when the lubricant does not provide a sufficient separating effect, because the start-up friction is higher than the kinetic friction.
Positive interaction of several components, whereby the cumulative effect of individual characteristics is multiplicative rather than additive.
Oils produced by means of chemical processes, as opposed to those extracted from the natural environment (mineral oils, animal and vegetable oils). Certain advantageous properties can be achieved, such as low tendency to carbonise, lower pour point, good resistance to chemicals and, often, excellent viscosity-temperature properties. Lubricants of this type make use of, amongst other substances, synthetic hydrocarbons, ester, polyglycols, fluorinated oils and silicone oils.
Thread Friction is determined using a screw test rig. According to DIN 946, the coefficient of friction for a threaded connection should be determined by tightening the fasteners and nuts. Threads dimensions, material and type of surface must be specified.
United States Department of Agriculture.
Volatile Corrosion Inhibitor (vapour-phase inhibitor) is an environmentally-friendly anti-corrosion additive.
Abbreviation for Viscosity Grade, which specifies the viscosity range of a lubricating grease.
Viscosity is a measure of the resistance of a fluid to flow due to the action of internal friction. The most important influencing factor on viscosity is temperature. Viscosity decreases as temperature increases, and vice versa. The allocation of viscosity grades is defined in DIN 51519. The higher the number, the thicker the fluid.
The four-ball test rig (German: Vierkugelapparat) is a piece of equipment that is used for testing lubricants at high surface pressures in the mixed-friction zone. As defined in DIN 51350, the VKA consists of a rotating ball bearing that slides against three stationary ball bearings. To test the maximum load capacity of the lubricant, a test force is applied to the rotating bearing, which is increased in stages until welding occurs in the four-ball system. An additional VKA test method is used to determine the wear coefficient of a lubricant under defined test conditions (test force, speed, time).
Paraffin-based mineral oil, highly refined to remove unstable components.
