THK EPF Series Finite Stroke Caged Ball LM Guide
The THK EPF Series is a caged ball LM Guide built with a finite stroke design. Since the balls don’t circulate, rolling resistance stays very consistent, making this guide ideal for applications that need smooth motion over a short stroke. Balls are held in place by spherical ball holders inside cages, rolling through four rows of circular-arc grooves on precision-ground LM rails and blocks. This DB construction gives the EPF Series high rigidity, especially against moment loads applied in the MC direction from a single rail.
The EPF Series is also a miniature type, and its mounting method matches THK’s Miniature LM Guide Model RSR-N, so the two are dimensionally interchangeable.
Each row of balls sits at a 45° contact angle, giving the EPF Series a four-way equal load structure. This keeps load ratings even across radial, reverse-radial, and lateral directions, letting it be used in any orientation. Because the ball cages are made from plastic resin, there’s no metal-to-metal contact with the balls, which reduces noise, lowers dust emissions, and extends product life. The spherical cage shape also holds lubricant well, supporting long periods of maintenance-free use.
There’s one model variant, EPF, with bolts mounted from above. Sizes range from 7 to 15, with basic dynamic load ratings from 0.90 kN to 3.71 kN and basic static load ratings from 1.60 kN to 5.88 kN.
