How to Convert cSt to SUS

How to Convert cSt to SUS
••• GaryKavanagh/iStock/GettyImages

Crude oil is refined and processed to create products with specific characteristics and uses. A key characteristic of refined oil is its viscosity, or ability to flow. This determines its lubricating abilities such as friction reduction and ability to cling to bearings. Drivers may be familiar with the SAE (Society of Automotive Engineers) scale used to describe engine oil, but viscosity is also measured in other units including centistokes (cSt) and Saybolt Universal Seconds (SUS).

    Establish the temperature at which the oil was tested to obtain the cSt value. This will usually be either 100 degrees Fahrenheit or 210 degrees Fahrenheit. That is 38 degrees Celsius or 99 degrees Celsius for metric calculations.

    Multiply the cSt value by 4.632 if the test temperature was 100 F. The result is the cSt value converted to SUS. For example:

    100 cSt tested at 100 F is equivalent to 463.2 SUS because 100 x 4.632 = 463.2.

    Multiply the cSt value by 4.664 if the test temperature was 210 F. The result is the cSt value converted to SUS. For example:

    100 cSt tested at 210 F is equivalent to 466.4 SUS because 100 x 4.664 = 466.4.


    • Viscosity varies with temperature and pressure. Standard calculations assume that the universally agreed temperatures and pressures are used. Under other conditions more complex calculations are required.

Related Articles

How to Convert Metric Tons to Barrels
Difference Between Hydraulic Fluid & Oil
What Is the Difference Between ISO Grades of Oil?
How to Measure the Density of an Unknown Oil
What Is a SAE 30 Oil?
How to Figure GPM Water Flow on an Existing Chiller
How to Convert Stokes to Poise
Properties of Kerosene
Test Your Knowledge on Middle School Science
How to Calculate Test Accuracy Ratios
How to Convert Gallons, Quarts, Pints and Cups
How to Convert Kilojoules to Kilocalories
How to Convert HP to BTU/hr
How to Convert API Gravity to Density
How to Calculate Hydraulic Cylinder Tonnage
Uses of a Bomb Calorimeter
To Calculate Arcsine, What Buttons Do You Press on...
How to Convert Pounds Per Square Foot to PSI
How to Multiply Vectors

Dont Go!

We Have More Great Sciencing Articles!