Technical Reference
How to read a model code, choose accuracy and preload, and specify rail length. These are the three questions that decide whether a guide performs or fails early.
Accuracy grades
| Grade | Typical use | Availability |
|---|---|---|
| C | General automation, transport axes | Interchangeable and matched |
| H | General machine tools | Interchangeable and matched |
| P | Machining centres, precision positioning | Interchangeable and matched |
| SP | High-precision machine tools, grinding | Matched set only |
| UP | Ultra-precision, measuring machines | Matched set only |
Preload selection
| Preload | Rigidity | Use when |
|---|---|---|
| Z0 (clearance) | Low | Low load, low vibration requirement, long travel |
| ZA (light) | Medium | Most machine axes — the default choice |
| ZB (medium) | High | Heavy cutting, high rigidity, matched set only |
Over-specifying preload is common. It raises rigidity but shortens travel life and increases heat. If you are unsure, send the load case and we will calculate it.
Reading a model code
Example: HGH20CA = HG series, square block (H), size 20, heavy-load C type, top tapped mounting (A). Rails follow HGR + size + mounting + length, for example HGR20R1200.
Rail length
Standard lengths are cut to order from 100 mm. Give us the stroke, the mounting hole pitch and the required end distance; we return the rail drawing for confirmation before production.