100 CST VISCOSITY EQUIVALENTS SAE ISO

While all of these have served useful purposes to one degree or another, most lubrication practitioners settle on and use one method as a basis for selecting products. To add to the confusion, two measures of temperature (Fahrenheit and Celsius) can be applied to most of these, not to mention that viscosity might be presented at either 40☌ (104☏) or 100☌ (212☏). There are SAE (Society of Automotive Engineers) grades for gear oils and crankcases (engines), AGMA (American Gear Manufacturers Association) grades for gear oils, SUS (Saybolt Universal Seconds), cSt (kinematic viscosity in centistokes), and absolute viscosity.

15.Through the years, lubricant users have been treated to a number of ways to designate viscosity grades of the lubricants used in manufacturing. 11.7 Example of an Engine Oil in different viscosities, showing SAE classification only

100 CST VISCOSITY EQUIVALENTS SAE ISO

74.0 Example of a Hydraulic Oil in different viscosities, showing ISO & SAE classifications Example of a Gear oil in different viscosities showing ISO, SAE & AGMA classifications: Below mentioned might help you to give you a more clear picture of it. Viscosity, wading through the numbers indeed. Issues with choosing the wrong viscosity fluid will be discussed at a later date.

Due to the effect of viscosity improvers, multi-grade oils such as engine oils are determined at the ISO VG 100☌ scale. Most Hydraulic, Industrial Gear, Compressor and Turbine oil viscosities are measured and sold at the ISO VG 40☌ scale. These additions reduce the span of the SAE 90 down to two ISO grade, the 150 and the 220 and the SAE 140 down to the ISO 320 and 460. Since this chart was developed, SAE has added two new viscosity ranges to deal with viscosity issues, the SAE 110 in between the SAE 90 and SAE 140 and the SAE 190 in between the SAE 140 and the SAE 250. Usually an ISO 220 can safely be used unless the gear box is exposed to low temperatures where an ISO 150 would be a better choice or high temperatures where the ISO 320 would work better. As you can see the SAE 90 is a wide range and covers the ISO 150 to the ISO 320 viscosity grades. It is not uncommon to find a gear box that requires a SAE 90 gear oil as this was the standard. However, you may find equipment that was manufactured prior to the ISO VG becoming a standard and here is where it may become confusing. The AGMA (American Gear Manufacturers Association) is mainly for stationary gear boxes and matches up with the ISO VG viscosity requirements. Most modern equipment falls into these categories. Seems easy enough until one discovers that there are several ways to describe the same viscosity.Īn easy way to look at it is to consider the application: is the application stationary or mobile?Ī general rule of thumb would be if the application is stationary then the ISO viscosity grade (VG) applies and if it is mobile then the SAE grades apply. Simply put, viscosity is the measure of resistance to flow, the higher the number the greater the resistance.

100 cst viscosity equivalents sae