Four-row recirculating ball bearing linear guide SR series

20 mm35 mm15 mm

Overview
This compact LM Guide has a low cross-sectional height and a four-row ball contact structure designed to receive large radial loads, making it optimal for horizontal guide units and applications requiring high radial rigidity.

• High accuracy
• Self-adjusting capability
• Designed for radial loads

Available sizes
15, 20, 25, 30, 35, 45, 55, 70, 85, 100, 120, 150

Types (summary)

• Models SR-W/WM — Basic dynamic load rating: 13.8 to 136 kN; Basic static load rating: 20.5 to 179 kN; Sizes: 15, 20, 25, 30, 35, 45, 55
• Models SR-V/VM — Basic dynamic load rating: 9.1 to 40.9 kN; Basic static load rating: 11.7 to 46.7 kN; Sizes: 15, 20, 25, 30, 35
• Model SR-T — Basic dynamic load rating: 226 to 411 kN; Basic static load rating: 282 to 537 kN; Sizes: 70, 85, 100, 120, 150
• Models SR-TB/TBM — Basic dynamic load rating: 13.8 to 136 kN; Basic static load rating: 20.5 to 179 kN; Sizes: 15, 20, 25, 30, 35, 45, 55 (flange / bolts mounted from below)
• Models SR-SB/SBM — Basic dynamic load rating: 9.1 to 40.9 kN; Basic static load rating: 11.7 to 46.7 kN; Sizes: 15, 20, 25, 30, 35 (flange / bolts mounted from below)

Structure and features
Balls run in four rows of precision-ground raceways on the LM rail and LM block; end plates in the block allow ball circulation. A retainer plate prevents ball drop when the block is removed from the rail. The low block height provides high rigidity and stable, high-precision linear motion.

• Compact with large radial load capacity — ball contact structure suited to high radial loads, ideal for horizontal guide units.
• Easy mounting accuracy — self-adjusting capability compensates for parallelism and leveling errors between two rails for smooth, accurate motion.
• Low noise — end plates ensure smooth, quiet ball circulation at turning areas.
• High durability — reduced differential slip under preload or biased loads; high wear resistance preserves long-term accuracy.
• Stainless-steel option — LM block, LM rail and balls available in stainless steel for corrosion resistance and use in demanding environments.

Characteristics and comparative notes

• Contact angle: 90° — offers higher radial rigidity and improved service life when loads are mainly radial compared with 45° models.
• Load rating and service life difference — for the same radial load and ball diameter, SR (90°) applies about 70% of the load of a 45° model, typically yielding more than twice the service life.
• Accuracy differences — machining errors on raceways affect SR (90°) less than 45° models; horizontal-direction errors are reduced versus 45° and 30° designs.
• Rigidity differences — for the same radial load P, radial displacement of SR (90°) is about 56% of that for a 45° contact-angle model, making SR advantageous when high radial rigidity is required.
• Application guidance — recommended when loads are mainly radial and high radial rigidity and accurate vertical/horizontal motion are required; for large reverse-radial, lateral loads or moments consider models optimized for multi-directional loads.

Specifications

• Series / denomination: SR (Radial Type)
• Contact angle: 90°
• Ball circulation: four rows with end plates and retainer plate to prevent ball drop
• Block: low cross-sectional height for high rigidity
• Materials: standard steel; M suffix indicates stainless-steel LM block, LM rail and balls (corrosion resistant)
• Available sizes: 15, 20, 25, 30, 35, 45, 55, 70, 85, 100, 120, 150
• Basic dynamic load rating (examples by type): SR-W/WM 13.8–136 kN; SR-V/VM 9.1–40.9 kN; SR-T 226–411 kN
• Basic static load rating (examples by type): SR-W/WM 20.5–179 kN; SR-V/VM 11.7–46.7 kN; SR-T 282–537 kN
• Standard LM rail pitches (F) vary by size class (typical: 60, 80, 105, 120, 150, 180, 210, 230, 250 mm)
• Standard / max LM rail length: multiple preset standard lengths; typical maximum standard length ~3,000 mm (stainless-steel models may have specific limits)
• Flange / mounting variants: TB/SB flange types (bolts from below) and W/V/T families (bolts from above)
• Grease nipple / lubrication: grease nipple provided on certain sizes and variants (refer to model-specific dimensions)