Lubricants are substances that reduce friction between moving parts. This document discusses the basic properties and types of lubricants. It defines lubricants as liquids or greases that decrease machine friction. It then covers key lubricant properties like viscosity, viscosity index, pour point, and flash point. Finally, it categorizes lubricants based on physical state, use, grade, and source; and discusses common additive types for mineral and synthetic lubricants.
4. What is lubricant?
• The substances which are used to decrease the force of
friction between the moving parts of machine in contact
• All liquids will provide lubrication to a degree
• There are two main groups, oil lubricants and grease
lubricants
Basic Lubricant Knowledge
5. Properties of lubricant
• Viscosity
• Viscosity Index
• Pour Point
• Flash Point
• Consistency or penetration number (Grease)
• Dropping Point (Grease)
• Structural Stability
Basic Lubricant Knowledge
6. Viscosity
• One of the main properties of any oil lubricant
• Is the measure of a lubricant’s resistant to flow
• Measured by petroleum industry in centistokes,
which numerically equal to mm2/s
• First consideration in selecting lubricant oil for
specific applications
Properties of lubricant
7. ViscosityProperties of lubricant
Operation condition VS viscosity needed
• Higher load requires high viscosity
• Higher temperature requires higher
viscosity
• Increased speed requires lower viscosity
8. Viscosity index
• The property of resisting changes in viscosity due to changes
in temperature
• The higher the VI number of oil, the less tendency for its
viscosity to change with the changes in temperature
Properties of lubricant
9. Pour Point
• The lowest temperature at which the oil will flow
Properties of lubricant
10. Flash Point
• Minimum temperature at which sufficient liquid is vaporized
to create a mixture of fuel and air that will burn if exposed
to a source of spark
Properties of lubricant
11. Consistency or penetration number (grease)
• Is defined as its resistibility to deformation under an applied
force, in other words its relative stiffness or hardness
Properties of lubricant
12. Dropping point
• The temperature at which the oil separates from the
thickener
Properties of lubricant
13. Structural stability
• The ability of the grease to resist changes in consistency
during mechanical working
Properties of lubricant
14. Classification of lubricants
Based on condition
• Solid lubricants
• Semi solid lubricants
• Liquid lubricants
Based on use
• Automotive lubricants
• Industrial lubricants
• Special lubricants
Basic Lubricant Knowledge
15. Classification of lubricants (Cont’d)
Based on grade
• Multi grade lubricants
• Mono grade lubricants
Based on source
• Mineral based lubricants
• Synthetic based lubricants
Basic Lubricant Knowledge
16. Mineral based lubricants
• The mineral lubricants get from crude oil through refine.
• Need to add additives, usually 10%
Classification of lubricants
17. Synthetic based lubricants
• Is a lubricant consisting of chemical compounds that are
artificially made (synthesized).
• Synthetic lubricants can be manufactured using chemically
modified petroleum components rather than whole crude oil
Classification of lubricants
19. Solid lubricants
• There are many types of solid lubricant used for different
applications
• Synthetic, metallic or mineral powders such as PTFE (Teflon),
copper, graphite
Classification of lubricants
