Marking on the Master LM Guide and Combined Use
Master LM Guide Indicators
All LM rails mounted on the same plane are marked with the same serial number. The LM rail marked with "KB" after the serial number is the master LM rail. The LM block on the master LM rail has its reference surface finished to a designated precision, allowing it to serve as the positioning reference for tables (see Fig.1). Normal grade LM Guides are not marked with "KB." Therefore, any one of the LM rails having the same serial number can be used as the master LM rail.

Reference Surface Indicators
In the LM Guide, the reference surface of the LM block is opposite the surface marked with the THK logo, and that of the LM rail is on the surface marked with a line (see Fig.2 ). Please specify if it is necessary to reverse the reference surface of the LM rail and block or if the grease nipple must be oriented in the opposite direction.

Serial Number Marking and Combined Use of an LM Rail and LM Blocks
An LM rail and LM block(s) used in combination must have the same serial number. When removing an LM block from the LM rail and reinstalling the LM block, make sure that they have the same serial number and the numbers are oriented in the same direction (Fig. 3).

Use of Joint Rails
When a long LM rail is ordered, two or more rails will be joined together to the desired length. When joining rails, make sure that the joint match marks shown in Fig. 4 are correctly positioned. When two LM Guide units with joint rails are to be arranged parallel to each other, they will be manufactured so that have axial symmetry (are mirror images of each other) as a set. If a large load is applied near the LM rail joint, the LM rail may deflect and cause misalignment. Therefore, we recommend securely fastening the joint section by pressing the LM rail against the reference surface using a set screw or the like and keeping the L dimension as short as possible (Fig. 4). For details, contact THK.
