This document discusses lubricants, their basic functions, characteristics, types, and selection criteria. Lubricants are used to reduce wear, heat, corrosion, and surface deformation in machines. Good lubricants have properties like high boiling point, low freezing point, high viscosity index, thermal stability, and corrosion prevention. Lubricants can be liquid, semi-solid, or solid and include oils, greases, and synthetic lubricants. Selection depends on factors like the machinery's speed, weight, and whether it is an internal combustion engine.

1. LUBRICANT
REDUCING FRICTION
BASIC FUNCTIONS
1. TO REDUCE WEARS
2. TO REDUCE HEAT FORMED
3. TO PROTECT METAL SUEFACE FROM CORROSION
4. TO REDUCE SURFACE DEFORMATION
A good lubricant possesses the following characteristics:
High boiling point.
Low freezing point.
High viscosity index.
Thermal stability.
Corrosion prevention.
High resistance to oxidation.

2. LUBRICANT
LIQUID SEMI SOLID SOLID
VEG. OIL
MINERAL
OIL
BLENDED
OIL
AXLE
GREESE
Ca GREESE
SODA BASE
GREESE
Li GREESE
GRAPHITE
MoS2
Olive Oil, Palm Oil,
Coconut Oil,
Cod leaver Oil
Petroleum Oil
3.4 Å

3. SYNTHETIC LUBRICANT
Organo Phosphate Di Basic Esters
ADDITIVES
Antioxidant
Slight polar organic acid
Anti-wear agents
Detergent-Dispersant
Pour point depressant
Viscosity Improvers

4. The flash point is the lowest temperature at which it can vaporize to form an ignitable mixture
in air.
The fire point is the temperature at which it will continue to burn for at least 5 seconds after
ignition by an open flame. At the flash point, a lower temperature, a substance will ignite briefly,
but vapor might not be produced at a rate to sustain the fire.
The cloud point is the temperature at which the fluid becomes hazy or Cloudy.
The pour point of a liquid is the lowest temperature at which it becomes semi solid and loses its
flow characteristics
SELECTION OF LUBRICANT
For slow moving and light weight machinery: Low viscous lubricant
For fast moving and heavyweight machinery: High viscous lubricant
For Internal Combustion Engine: High Flash and Fire Point