| Arithmetical mean roughness (Ra) | Max. height (Ry) | 10-point mean roughness (Rz) | Standard length of R max. Rz ℓ (mm) | Triangular idication | ||
|---|---|---|---|---|---|---|
| Preferred Number Series | Cut-off value π C(mm) |
Indication of Surface Texture on drawings | Preferred Number Series | |||
| 0.012α | 0.08 |  |
0.05s | 0.05z | 0.08 |  |
| 0.025α | 0.025 | 0.1s | 0.1z | |||
| 0.05α | 0.2s | 0.2z | 0.25 | |||
| 0.1α | 0.8 | 0.4s | 0.4z | |||
| 0.2α | 0.8s | 0.8z | 0.8 | |||
| 0.4α |  |
1.6s | 1.6z |  |
||
| 0.8α | 3.2s | 3.2z | ||||
| 1.6α | 6.3s | 6.3z | ||||
| 3.2α | 2.5 |  |
12.5s | 12.5z | 2.5 |  |
| 6.3α | 25s | 25z | ||||
| 12.5α | 8 |  |
50s | 50z |  |
|
| 25α | 100s | 100z | 8 | |||
| 50α |  |
200s | 200z | ~ | ||
| 100α | - | 400s | 400z | - | ||
Caution
- The interdependence for 3 classes is not strictly enforced.
- The evaluation lengths of Ra, Rmax and Rz: Five times the cut-off value and standard length