Linear Bearing LM and LME Symbology
Linear bearings are used in many different engineering and mechanical applications. In order to ensure accuracy and precision in the selection of linear bearings, a standard code system is used to label and identify them. This article will discuss common symbols used in these codes and how they can be applied to different types of linear bearings.
First of all, the common codes LM and LME indicate linear motion bearings with the letter L denoting that the bearing is a Linear. The first digit after the letter denotes the type of bearing. For example, an LM2 stands for a linear bearing with a load rating reduced by 25%. LME3 stands for a linear bearing with a load rating increased by 25%.
The second two digits of the code refers to the bearings internal diameter in millimeters. For example, a bearing with LM26 code has an internal diameter of 26mm. The final two digits of the code refers to the bearings radial width in millimeters. So for this example, the bearing has a radial width of 6mm.
The load rating for a given bearing is indicated by the letters SB or LS after the initial code. SB stands for static bearing load, while LS stands for dynamic bearing load. Generally speaking, dynamic loads are greater than static loads, so bearings with LS code have a higher load rating than those with an SB code.
In addition to the common linear bearing code of LM & LME, there are other codes used to describe different types of linear bearings. These codes include ML, MLL and MLE. ML codes indicate full-complement linear bearings, which are self-aligning bearings that can operate with less clearance than a standard bearing. MLL and MLE codes indicate non-self-aligning bearings for use in applications where a high degree of accuracy is required or where the ability to operate with minimal clearance is desired. Additional codes such as LN, LV, SL and ST are used to denote pillow blocks, thrust collars and other linear bearing components.
Finally, there are special codes used to signify additional features of a linear bearing. These code symbols may include N (for grease fitting), SL (for shock-load protection), MT (for metric measurements) or a number (indicating a specific oil rating).
As you can see, a standard system of codes is used to identify and label different types of linear bearings. By understanding the meaning of these codes, you can ensure you are selecting the right components for your application.
