Tech Talk Blog

Manufacturer’s of plain bearing materials will sometimes reference K factor which is a way of measuring the actual wear of the material over time. What is left out of the equation is how that K factor varies depending on the PV of the application. As an example, Delrin AF is a popular material for plain bearings. If you have an application wher your load is 45 psi and your speed is 100 feet per minute, your approximate K factor is 51. Take that same material and decrease the load to 20 psi and increase the speed to 350 feet per minute and your K factor increases to 70. That’s almost 40% greater wear. Another example is Ertalyte TX, a bearing grade PET from Quadrant. The K factor at 10 psi and 100 feet per minute is approximately 21. At 45 psi and 360 feet per minute the K factor increases to 464. So consider K factor as you do PV and coefficient of friction. These are numbers that are always relative to all of the surrounding factors in the bearing design.