#CST VISCOSITY MEANING ISO#
#CST VISCOSITY MEANING TV#

They usually are used in applications where a liquid lubricant would run out. Greases are fluid lubricants enhanced with a thickener to make them semi-solid. However, it is still relevant for selection of the correct grease for a specific application. Grease viscosity, traditionally called consistency, cannot be measured using the tests noted above. The kinematic viscosity is determined by using a capillary viscometer in which a fixed volume of fluid is passed through a small orifice at a controlled temperature under the influence of gravity. This test will be discussed in more detail later.Ī more familiar viscosity term is kinematic viscosity, which takes into account the fluid density as a quotient of the fluid’s dynamic viscosity and is usually reported in stokes (St) or centistokes (1 St = 100 cSt). A common tool used to measure dynamic viscosity is the Brookfield viscometer, which employs a rotating spindle that experiences torque as it rotate against fluid friction. Dynamic viscosity is a measurement of a lubricant’s internal friction and it is usually reported in units called poise (P) or centipoise (1 P = 100 cP). This force is known as dynamic viscosity. Force is required to make the plates move, or overcome the fluid’s film friction. Assume that a lubricating fluid is compressed between two flat plates, creating a film between the plates. Viscosity can be used to control a fluid’s sealing ability, which results in lower consumptionĪs mentioned above, viscosity is a physical measurement of a fluid’s internal resistance to flow.Viscosity determines the ease with which machines can be started in low-temperature conditions or can be kept running in high-temperature conditions.Viscosity affects heat generation and removal in bearings, cylinders and gears.Viscosity affects fluid film thickness under certain conditions of temperature and load in lubrication applications.There are several reasons for this, including, but not limited to: It is clear that – for the majority of the players in the lubricant industry – the proper viscosity of a fluid is the most important attribute in proper lubrication.

#CST VISCOSITY MEANING ISO#

Lubricant marketers usually sell their lubricants according to specific viscosity grades, such as SAE 15W-40, ISO 46 and AGMA 3. Original equipment manufacturers often specify the lubricant to be used in their equipment by product type and viscosity. The presence of viscosity information on almost all lubricant marketers’ technical literature is an indication that it also is important in the marketing of lubricants. This ad illustrated just how important it is to consider viscosity when choosing the proper lubricant for a specific application. The resistance to flow, or viscosity, of the second oil had increased dramatically with the decrease in temperature.

#CST VISCOSITY MEANING TV#

A good example of this was provided in one of the TV ads, which showed two oils being cooled until one continued to flow out of the bottle readily, while the second dropped out in blobs. Simply stated, viscosity is a measure of a fluid’s internal resistance to flow. These advertisements make it seem like viscosity is a complex chemical property of the fluid, when in fact it is a measurement of a physical property. In recent years, some large lubricant marketers have run advertisements on TV that highlight the importance of viscosity breakdown.

This paper will summarize some of the more commonly used viscosity standards, describe the tests used to measure viscosity, and eliminate some of the confusion all of these standards may create for the end user. Some examples are SUS, cSt, cP, ISO, SAE engine, SAE gear and AGMA it’s enough to make a person’s head start to spin. That doesn’t sound too difficult, does it? Unfortunately, new temperature, speed and pressure demands on lubricating fluids have changed over the years, resulting in several different measurements and classifications being created to describe lubricant viscosity. Simply stated, viscosity is defined as the internal resistance of a fluid to flow. By John Sander, VP Technology, Lubrication Engineers Inc.

Cst viscosity meaning