N grade to micrometers Ra
Type a value in N to get it in µm Ra instantly.
0.03789µm Ra
That's 1.52× as rough as an optical mirror, while a ground surface is 11× rougher. A human hair is about 1,847 times that height.
Convert the other way: µm Ra to N
What it means
How rough is that?
Ra is an average of the deviations, so two surfaces with the same Ra can feel and wear quite differently. Ra and Rq relate exactly only for a sine profile.
The math
How to convert N to µm Ra
N grades double at every step: Ra = 0.025 × 2^(N − 1) micrometers, so N6 is 0.8 µm and N7 is 1.6 µm. The other units are plain multiples.
Example: 1.6 N = 0.0378929 µm Ra.
Every unit
Your roughness in every unit
Tables
N to µm Ra conversion table
| N | µm Ra |
|---|---|
| 0.025 N | 0.0127185 µm Ra |
| 0.05 N | 0.0129408 µm Ra |
| 0.1 N | 0.0133972 µm Ra |
| 0.2 N | 0.0143587 µm Ra |
| 0.4 N | 0.0164938 µm Ra |
| 0.8 N | 0.0217638 µm Ra |
| 1.6 N | 0.0378929 µm Ra |
| 3.2 N | 0.11487 µm Ra |
| 6.3 N | 0.984916 µm Ra |
| 12.5 N | 72.4077 µm Ra |
| 25 N | 419,430 µm Ra |
| 50 N | 1.407×10¹³ µm Ra |
µm Ra to N conversion table
| µm Ra | N |
|---|---|
| 0.025 µm Ra | 1 N |
| 0.05 µm Ra | 2 N |
| 0.1 µm Ra | 3 N |
| 0.2 µm Ra | 4 N |
| 0.4 µm Ra | 5 N |
| 0.8 µm Ra | 6 N |
| 1.6 µm Ra | 7 N |
| 3.2 µm Ra | 8 N |
| 6.3 µm Ra | 8.97728 N |
| 12.5 µm Ra | 9.96578 N |
| 25 µm Ra | 10.9658 N |
| 50 µm Ra | 11.9658 N |
Quick answers
Quick answers
- How many µm Ra is 1 N?
- 1 N is 0.025 µm Ra.
- How many µm Ra is 10 N?
- 10 N is 12.8 µm Ra.
- How many µm Ra is 1.6 N?
- 1.6 N is 0.0378929 µm Ra.
The units
About these units
N grade (N)
The grade numbers on older drawings. Each step doubles the roughness.
Micrometers Ra (µm Ra)
The international standard for average roughness.
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