Linear guides are a critical component in medical devices, automotive assembly, warehouse automation, semiconductor equipment, and hundreds of other applications. Below are the questions our engineering team fields most often—updated with current product data, spec tables, and relevant MISUMI product pages.
Technical specifications
Are the ball bearings in linear guide blocks retained?
Yes—all ball bearings on MISUMI brand linear guides are fully retained, meaning the balls stay in place when the block is removed from the rail. For THK linear guides, retained ball designs include part numbers starting with SHS, SSR, SRS, and SHW series.
Retained bearings simplify disassembly, reduce contamination risk, and are especially valuable during maintenance in tight spaces.
What is the seal material of MISUMI miniature linear guides?
MISUMI miniature linear guides use Nitrile Rubber (NBR) end seals. NBR offers good resistance to oils and greases, making it suitable for standard industrial environments. For applications requiring resistance to hydraulic fluids, extreme temperatures, or specific chemicals, contact MISUMI to discuss material options.
What are the dimensional tolerances for MISUMI linear guides?
MISUMI publishes the following standard tolerances. Tighter precision grades are available on select series—check the individual product spec sheet.
| Dimension | Tolerance | Notes |
|---|---|---|
| W1 (overall guide width) | ±0.005 mm |
Applies to MISUMI standard series |
| W (block width) | ±0.05 mm |
— |
| Rail width | ±0.005 mm |
Tighter than block—rail drives system straightness |
The tighter rail tolerance relative to block width is intentional: rail straightness has a much greater impact on overall system accuracy than block width variation.
Can blocks be added to or swapped on an existing rail?
Only on Interchangeable Linear Guides. Because these are manufactured to a common precision standard, blocks and rails from the same series are fully interchangeable—you can buy additional blocks or replacement rails independently and maintain the original precision spec.
All other linear guide types (standard, high-precision, THK catalog guides, etc.) are sold as matched sets. Mixing blocks and rails across sets is not recommended and voids the precision guarantee.
Can the clips attached to the rail during shipping be used as block stoppers?
Using shipping clips as operational stoppers can result in block ejection, equipment damage, and safety hazards. For proper end-of-travel control, MISUMI offers dedicated stopper accessories:
- Stopper bolts
- Stopper plates
- Linear stoppers
Can linear guides be used on a wall or ceiling?
Yes. MISUMI, THK, Bosch Rexroth, Thomson and most other recirculating ball linear guides carry the same dynamic load rating regardless of mounting orientation. This is because the ball recirculation path distributes load symmetrically around the rail.
Products and sourcing
What other brands of linear guides does MISUMI carry?
In addition to the MISUMI brand, we stock a full range of linear guides from the following manufacturers:
Available in miniature through heavy-load sizes. Use the filters on each brand page to search by series, block type, accuracy class, and preload.
What grease is used in MISUMI and THK linear guides as standard?
Grease selection varies by guide size and type. Here are the standard fills:
MISUMI brand guides
THK linear guides—grease varies by series and size:
| Grease type | Applicable series and sizes |
|---|---|
| AFF | SRS (size 5–15), SHW (size 12–17) |
| AFB-LF | SHS, SSR, HSR, SR (size 15–65) · SHW (size 21–50) · HRW (size 17–50) · SRS (size 20–25) |
When regreasing, always use the same grease type originally specified, or confirm compatibility with the manufacturer. Mixing incompatible grease formulations can lead to accelerated wear.
How do I calculate the lifespan of a linear guide?
Linear guide lifespan is calculated using the standard L10 rated travel life formula, which accounts for the guide’s basic dynamic load rating (C), the actual applied load (P), and a load factor. The relationship follows:
L = 50 × (C / P)3 [km of travel, for ball guides]
The inputs you need: applied load per block, direction of load, travel speed, duty cycle, and the guide’s rated dynamic load capacity (found in the series datasheet).
For a full worked example, see “Calculation of Life Span of Linear Systems” in the MISUMI Technical Data catalog:
Can I get linear guide rails cut to a custom length?
Yes—in two ways depending on the brand:
- MISUMI brand rails—configurable at order time in 1 mm increments directly from the product page.
- THK and Bosch Rexroth rails—available through the MISUMI Rail Cutting Service in 1 mm increments with a 2-day lead time.
- Other brands (IKO, Thomson)—check the individual product page for available configurations and lead times.
