Lubezine Magazine Vol. 9 April - June 2014 | Page 22

TECHNOLOGY

FEATURE
OIL STANDARDS

HOW TO READ
A CAN OF OIL

By J S Evans,
B.Sc.

W

hen purchasing a can,
drum or
tankerful of oil, it is
important to realise
that a number of
international classification systems are
used to describe the product and its uses.
The classifications, which include ISO,
SAE, API, CCMC, SABS, JAMA and ISLS,
are each followed by a series of numbers
and letters detailing either the viscosity
of the oil or its performance properties.
This article will look at the viscosity classifications of lubricating oils.

Viscosity
The most important property of an oil is
its viscosity. This is defined as the oil’s
resistance to flow at a specified temperature under the force of gravity. It is a
measure of the oil’s ‘thickness’; ‘thick’
oil has a high viscosity while ‘thin’ oil
has a low viscosity. A fluid’s resistance
to flow is known as kinematic viscosity
and this is the measurement that is of
greatest concern to industries which
use lubricants. Kinematic viscosity
is measured in centistokes (cSt) and
one centistoke equals one millimetre
squared per second.
Kinematic Viscosity = 1 Centistoke (cSt) =
1 mm2/s
It is important to note that as temperature increases, viscosity decreases, so
one must always state the temperature
at which viscosity is measured, otherwise the reading will be meaningless.
Two industry standards are used when
20

LUBEZINE MAGAZINE | February-April 2014