Linear Bearings — Profile Rail, Round Shaft, Ball Bushings
Specify type, size, preload, accuracy, seals, and length. We cross to multiple manufacturers and return best-fit options with lead times.
Guide Types — What’s the Difference?
Profile Rail (Ball)
Square rails with recirculating balls. High stiffness, low friction, and preload options (Z0–Z2) for precise, repeatable motion. Sizes 7–65; grades N/H/P/SP/UP. Add seals/scrapers and lube ports for life in dirty environments.
Best for: precision automation, machine tools, pick-and-place, gantries,
Profile Rail (Roller)
Same geometry as ball type, but rolling elements are cylindrical rollers—boosting load & moment capacity at similar sizes. Great for heavy gantries and machine tools with high cutting forces.
Best for: life-science instruments, optics stages, small pickers, and light payload XY platforms.
Minature Guides
Compact versions (sizes ~5–15) for tight spaces and low moving mass. Stainless, low-particle greases, and cleanroom options are common. Perfect for instrumentation and optics.
Best for: simple linear mechanisms, packaging accessories, guarded slides, and retrofit axes where alignment is challenging.
Round Shaft + Ball Bushing
Hardened round shafts with open/closed bushings. Very forgiving to misalignment, simple to mount, and cost-effective. Use supported shafts for long spans.
Best for: cost-effective linear motion, adjustable tooling, and applications with modest accuracy needs.
Polymer Plain Bearings
Self-lubricating liners on round shafts. Excellent in dust, washdown, or where grease is a problem. Lower load/accuracy than profile rail but low cost and maintenance.
Best for: long-stroke round-shaft axes, fixtures, conveyors, and add-on linear guidance.
Crossed-Roller / Dovetail Slides
For very high precision and smoothness. Crossed-roller ways offer micron-class straightness; dovetails are rigid and compact but require lubrication and careful alignment.
Best for: food & beverage, washdown packaging, outdoor installations, and chemical exposure.
Compare Linear Bearing Technologies
| Criteria | Profile Rail (Ball) | Profile Rail (Roller) | Miniature Guide | Round Shaft + Bushing | Polymer Plain | Crossed-Roller / Dovetail |
|---|---|---|---|---|---|---|
| Rigidity | High | Very high | Medium | Low–medium | Low–medium | Very high (CR) / High (Dovetail) |
| Load & moments | High | Very high | Low–medium | Medium (supported) | Low–medium | High |
| Friction / smoothness | Very low | Very low | Very low | Low | Low–medium (dry) | Very low (CR) / Low (Dovetail) |
| Misalignment tolerance | Low (needs flat/parallel) | Low | Low | High | High | Low (needs precision base) |
| Accuracy potential | ±5–20 μm | ±5–15 μm | ±10–30 μm | ±50–200 μm | ±100–300 μm | ±1–5 μm (CR) |
| Environment | Seals/scrapers recommended | Seals/scrapers recommended | Cleanroom options | Great in dirty with seals | Excellent in dust/wet | Clean, lubricated |
| Relative cost | $$ | $$$ | $–$$ | $ | $ | $$$ |
| Best for | Precision automation, gantries | Heavy loads, machine tools | Instruments, optics, small XY | Fixtures, simple slides | Washdown/dusty, low-maintenance | Metrology, high-end stages |
What to Specify
Profile vs. Round?
Profile rail carries higher moment loads & accuracy; round shafting is tolerant to misalignment and economical.
Preload & Accuracy?
Preload improves stiffness/precision; grades N/H/P/SP/UP set straightness & height tolerances.
Seals & Materials?
End seals and scrapers keep debris out; stainless, nickel, or chrome plating for washdown/corrosion.
Rule of thumb: when in doubt, select the **smallest rail that meets load/moment and deflection** with a **light preload**, then add protection for the environment. We’ll validate L10 life and straightness in your stack-up.
FAQ
Build Your Linear Bearing Spec
Profile rails & blocks, round shafts & bushings, or wheel guides. Fill what you know — your Spec ID updates live and we’ll cross to manufacturers.
Rule of thumb: when in doubt, select the **smallest rail that meets load/moment and deflection** with a **light preload**, then add protection for the environment. We’ll validate L10 life and straightness in your stack-up.