The first step to understanding the Coefficient of Friction (COF) of engineering plastics when compared to that of steel is grasping that the COF is not based on a material’s property alone, but is rather a system’s property. One part/piece/component does not make a system and therefore requires the evaluation of the total solution.
The values for the COF of engineering plastics can be used for comparative purposes in helping the design engineer in selecting the appropriate material option for the intended application. The main parameters that affect the COF in the evaluation and selection of engineering plastics are:
- relative sliding velocity
- geometry of the parts in contact
- nature, roughness and hardness of the steel mating surface
- total operating time
- nature of any intermediate medium, e.g. water, lubricants, abrasive particles
- specific properties of the plastics material
This data has been determined on a specific tribological device under a set of standard laboratory conditions, and should not be used to predict the frictional behavior of the materials under real service conditions which may very well be quite different than those used in our laboratory tests.
Please also note that the values for the COF of Quadrant’s engineering plastics provided in our technical literature should not be compared with other brands of engineering plastics as they were likely tested under a completely different set of test conditions which may result in values that are lower or higher than our published values. You can count on Quadrant’s material data to be accurate for the FINISHED material and not pre-manufacturing resin data.
Quadrant always recommends that the user run a practical test under real service conditions in order to determine the actual COF and performance of an engineering plastic and/or to compare different engineering plastics in an application.
For detailed information on the COF of Quadrant’s engineering plastics, please get in touch with the bearing experts. Visit TriStar's Video Learning Center to learn more about several of the most popular Quadrant materials.