What is L10? The L10 life is the number of revolutions or hours that 90% of a group of apparently identical bearings will complete or exceed before fatigue is expected to occur. In other words, 10% of the group is not expected to achieve the L10 life. The rating life can be calculated in terms of millions of revolutions or hours by using the bearing
The basic load rating is a reference value only, to be used for selection of an adequately sized bearing to provide the desired L10 life in a given application. The L10 rating standard was originally established by the ABMA – American Bearing Manufacturers Association. Based on years of analysis very few bearings actually fail because of “fatigue.” The cause is usually another factor, such as lubricant failure or contamination.