What is the unit of surface finish?
The surface finish of a part can be measured using one of two roughness value systems: arithmetic average roughness or geometric average roughness. The roughness by arithmetic average (Ra) is the accepted standard and can be measured in English (microinches) or metrics (microns) units.
What does surface finish N6 mean?
Bearing Surfaces…. N6 = 0.8mm (micro.m) Fine lapped surfaces…. N1 = 0.025mm (micro.m)
How do you calculate surface finish?
That means you:
- Measure height across the microscopic peaks and valleys.
- Calculate the SQUARE of each measurement value.
- Calculate the MEAN (or average) of those numbers (squared).
- Find the square ROOT of that number.
What is the Ra value in microns?
0.1 μm
General requirements end the surface roughness value for Ra=0.1 μm, the value of flatness of 0.8 μm below.
What is Ra 0.8 surface finish?
Equivalent Ra values for Surface Finish Grade Numbers
| Roughness N ISO Grade Numbers | Roughness values Ra micrometers (µm) | Roughness values Ra microinches (µin.) |
|---|---|---|
| N8 | 3.2 | 125 |
| N7 | 1.6 | 63 |
| N6 | 0.8 | 32 |
| N5 | 0.4 | 16 |
What is N9 finish?
N9 Pure SilverTM is an antibacterial and hygiene finish applied on fabrics or garments. It is a revolutionary particulate silver-based technology that, on contact, neutralises odour-causing bacteria, keeping textiles fresher for longer. N9 Pure Silver™ is non-leaching.
What is the value of N7?
“EQUIVALENT SURFACE FINISH N5 N6 N7 N8 N9”
| Roughness values Ra | Roughness values Ra | Roughness |
|---|---|---|
| 8.3 6.3 | 250 | N9 |
| 3.2 | 125 | N8 |
| 1.6 | 63 | N7 |
| 0.8 | 32 | N6 |