Linear guide unit with recirculating ball carriage RSR series

corrosion-resistantcompacthigh-precision

Overview
Miniature full-ball LM guide capable of receiving loads in all directions. Single-rail design with balls running in two rows of precision-ground raceways on the LM rail and LM block; end plates in the block allow ball circulation and provide infinite straight motion (infinite stroke). Compact block geometry combined with large-diameter balls ensures high rigidity in confined spaces.

Highlight tags

• High accuracy
• 4-way equal load
• Miniature
• Long-block LM Guide (selected models)
• Wide block (selected models)
• Top-mounted bolts

Types / Model lineup

• RSR-M — Basic dynamic load rating: 0.18 kN; Basic static load rating: 0.27 kN; Size: 3.
• RSR-WM / WVM — Basic dynamic load rating: 0.25 to 6.01 kN; Basic static load rating: 0.47 to 9.08 kN; Sizes: 3, 14.
• RSR-N — Basic dynamic load rating: 0.214 to 0.3 kN; Basic static load rating: 0.384 to 0.44 kN; Sizes: 2, 3.
• RSR-WN — Basic dynamic load rating: 0.395 to 0.39 kN; Basic static load rating: 0.682 to 0.75 kN; Sizes: 2, 3.

Structure and features

• Double-row balls circulate inside the LM block via end plates, enabling infinite stroke.
• Compact LM block shape and large-diameter balls provide high rigidity in all directions.
• Ultra-compact design reduces cage-displacement issues common to finite-stroke guides, increasing reliability.
• Single-rail operation accepts loads from any direction and tolerates small moment loads; RSR-W variants use more effective balls and a wider rail to improve moment rigidity while keeping compactness and straight motion durability.
• Corrosion-resistant option: LM rail, LM block and balls available in stainless steel (model suffix 'M').

Accuracy of the mounting surface
RSR uses Gothic-arch grooves for the ball raceways. When using two rails in parallel, mounting surface errors can increase rolling resistance and impair smooth motion. Refer to flatness requirements in the dimensional data.

Notes on lubrication and seals

• RSR2 and RSR3 models lack a lubrication hole; apply lubricant directly to the LM rail raceways when required.
• RSR2N, 2WN, 3M and 3N models do not include contamination-protection seals.

Tapped-hole LM rail type
Rails are available with bottom-tapped holes for bottom mounting or enhanced contamination protection. Tapped-hole types are offered for precision grade and lower; tap sizes vary by model (examples: RSR2W M1.6 through, RSR3W M4 through, RSR14W M5 through).

Recommended tightening torques (selected)

• RSR 2N: Block 0.09 N·m / Rail 0.03 N·m (use flathead machine screw for precision equipment)
• RSR 2WN: Block 0.28 N·m / Rail 0.138 N·m
• RSR 3M: Block 0.09 N·m / Rail 0.09 N·m (use austenitic stainless hex-socket-head bolts)
• RSR 3N: Block 0.19 N·m / Rail 0.09 N·m
• RSR 3WM / 3WN: Block 0.19 N·m; rail torque varies (see applicable bolt type guidance)

Standard lengths and maximum lengths (summary)
Unit: mm
Examples: RSR2N: 32, 40, 56, 80, 104 / Pitch F = 8 / Max length = 200; RSR2WN: 40, 60, 70, 80, 100, 180 / F = 10 / Max length = 200; RSR3: 30, 40, 60, 80, 100 / F = 10 / Max length = 220; RSR3W: 40, 55, 70 / F = 15 / Max length = 335; RSR14W: 110, 150, 190, 230, 270, 310, 430, 550, 670, 790 / F = 40 / Max length = 1800.

Dimensional / functional notes

• LM block total length L in tables includes dust-proof parts (code: UU).
• Basic load ratings are specified for radial-direction loads; use equivalent-load calculations for reverse radial or lateral loads.
• When removing the LM block from the rail, balls may fall out—handle with care.

Technical specifications

• Product type: Miniature Full-Ball LM Guide (Model family: RSR)
• Brand: THK
• Model variants: RSR-M, RSR-WM, RSR-WVM, RSR-N, RSR-WN (multiple sizes per model)
• Available nominal sizes: 2, 3, 14 (model-dependent)
• Ball circulation: double-row precision-ground raceways with circulating balls in LM block
• Materials: Stainless-steel versions (suffix M) for LM block, LM rail and balls available for corrosion resistance
• Basic dynamic load ratings: examples from 0.18 kN up to 6.01 kN depending on model
• Basic static load ratings: examples from 0.27 kN up to 9.08 kN depending on model
• Maximum LM rail lengths: model-dependent (examples above)
• Lubrication: some models lack lubrication holes—lubricate rail raceways directly as required
• Tapped LM rail option: available for selected models (tap sizes vary by model)
• Recommended mounting bolt torques: model-specific (values listed above)