THK Develops Linear Motion Guide Accuracy Standards

September 5, 2006 – To meet a wide range of application requirements, THK has developed new accuracy standards. The accuracy grades created by THK in 1973 have been adopted as the Global Standard. After 30 years, THK’s manufacturing capability has improved the accuracy standards of LM Guides. In addition to revising specifications, THK has added two new accuracy standards (Ct7 and Ct5) to accommodate a wider range of application requirements. THK accuracy grades range from sub-micron to normal.

The accuracy of an LM Guide is specified in terms of running parallelism, dimensional tolerance of height and width and the height and width difference between a pair of LM guides (when 2 or more LM blocks are used on one rail or when 2 or more rails are mounted on the same plane). Running parallelism indicates the tolerance for parallelism between the LM block and the LM rail reference surfaces when the LM block travels the whole length of the LM rail secured on the reference surface using bolts.

THK’s new accuracy standards apply to a variety of caged ball and caged roller LM guides, as well as standard LM guides, from the THK line.

THK manufacturers the widest range of linear motion products including conventional LM guides, ball screws, mechanical actuators and ball splines and more. All THK products have been designed and manufactured to meet the strictest requirements. THK’s experienced Global Engineering Team can provide customized linear motion solutions with our standard linear motion products as well as our mechatronics products for your most demanding applications.