Type PMM Miniature Ball Slides: Achieving Compact, Low Friction, and Accurate Linear Motion

Compact – Low friction – Accurate. The miniature ball slide type PMM is a compact solution for smooth and accurate linear motion that fits in narrow spaces to transfer light to moderate loads.

The miniature ball slides were specifically designed for use in the semiconductor industry and medical devices, where they play a crucial role in accurately positioning samples under microscopes. The slide carriage and center rail are comprised of high-precision finished table parts that feature integrated raceways. Additionally, the ball cage has been specially designed to deliver exceptional performance in terms of smoothness and low friction.

Available sizes and stroke lengths

Miniature linear slides PMM series are offered in three sizes; PMM 05, 1, and 2. Within a size, there are different lengths, varying from 10 mm - 80 mm. The stroke lengths vary between 5 and 70 mm while the dynamic load capacity is 23 N - 429 N.

Boundary dimensions of miniature ball slides:
Type PMM 05, width x height: 7 x 4 mm.
Type PMM 1, width x height: 10 x 6 mm.
Type PMM 2, width x height: 15 x 8 mm.

Click here for product information, brochure, and 3D CAD models.

Easy mounting of miniature ball slides

Easy mounting and installation of the miniature ball slides in the application is possible by using the standard threaded holes in the center rail and the carriage. The slides are pre-lubricated with a small amount of oil and are ready to use.

Customer-specific solutions

Engineers can request customized versions of the PMM miniature linear slides that meet individual requirements, e.g.:

  • Custom stroke length

  • Customized slide width – length

  • Cleanroom or vacuum compatible

  • Lubrication

  • Higher load-carrying capacity

  • Different hole pattern

  • Specified moving force

Please contact PM’s product specialists for more information.

High runout accuracy with smooth movement

Miniature ball slides are preloaded without backlash by geometry pairing, using precision balls with a slight oversize of 0.5 microns. This allows the preload and stiffness to be set accurately and guarantees a backlash-free, smooth accurate, and repeatable movement.

The four-point contact between the balls and the raceway, the high-precision ground raceways, and the design of the ball cage result in a very smooth motion with little friction and low starting force.

Straight-line accuracy and flatness accuracy are depending on size and length, they range from 3 – 6 microns for the standard precision class. Higher specifications are to be requested.

Material and design

The carriage and the center rail are made of stainless steel and through-hardened. The ball cage material is stainless steel. The design of the cage, a U-shaped precision strip with ball pockets on both sides, makes it less sensitive to cage creep.

Cage creep or cage migration is a phenomenon whereby the cage slowly creeps out of its original position. In most cases, it happened due to a poor alignment of the slide in the assembly, high speeds/accelerations or in vertical mounting orientations. As the cage creeps away from its centered position it prevents the carriage from reaching its maximum stroke. The design of the cage reduces the risk of cage creep.

Technical data


 05, 1 and 2

Travel range

 5...70 mm


 up to 3 microns/ 30 mm


 8 m/s2

Operating temperature

 -40 up to 120 °C

Applications for miniature linear slides

Miniature slides find their primary application in the semiconductor industry, as well as in optical, medical, and measurement devices.

In short, anywhere space is limited and precise, smooth movement combined with high reliability is required.

3D CAD models

This product page provides access to downloadable datasheets and CAD files for the miniature ball slides type PMM. 

Download product datasheet

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