Micrometers Ra to N grade
Type a value in µm Ra to get it in N instantly.
7N
That's about the same as a machined surface. A human hair is about 43.75 times that height.
Convert the other way: N to µm Ra
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 µm Ra to N
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 µm Ra = 7 N.
Every unit
Your roughness in every unit
Tables
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 |
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 |
Quick answers
Quick answers
- How many N is 1 µm Ra?
- 1 µm Ra is 6.32193 N.
- How many N is 10 µm Ra?
- 10 µm Ra is 9.64386 N.
- How many N is 1.6 µm Ra?
- 1.6 µm Ra is 7 N.
The units
About these units
Micrometers Ra (µm Ra)
The international standard for average roughness.
N grade (N)
The grade numbers on older drawings. Each step doubles the roughness.
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