D
Deutsches Institut für Normung e. V., the German Institute for Standardization, is a nonprofit organization that develops and publishes standards on a wide variety of topics. Headquartered in Berlin, Germany, DIN is Germany’s national standards organization. DIN standards are synchronized with the rest of the world.
The ease with which grease may be transferred from its container to its point of application. Mostly used in discussion of grease dispensing systems, where it includes both the properties of pumpability and feedability.
Refers to the temperature observed in a laboratory test where a small quantity of lubricating grease is heated until a drop of material separates from the grease. That temperature is adjusted according to ASTM D 2265. The dropping point is not the melting point of lubricating grease. Dropping point is used in many grease specifications. However, this test has very limited relevance to service performance. Dropping point should not be used to determine the upper operating temperature of a grease. To estimate how grease performs at high temperature, certain bearing life tests may be helpful.
Dry or solid lubricants form films that reduce friction without the need for oil. Dry lubricants are often used in locks, certain bearings, and applications at high temperatures and oxidizing conditions. Examples include graphite, molybdenum disulfide, boron nitride, PTFE (polytetrafluoroethylene) and certain soaps.
Also called kinetic friction, the resistance to motion of contacting bodies as they move relative to one another.
The ratio between the applied shear stress and rate of shear of a liquid. The dynamic viscosity can be measured by placing the liquid between two parallel plates, and measuring the force required to move one plate while holding the other plate fixed.