Microinches Ra to micrometers Ra
Type a value in µin Ra to get it in µm Ra instantly.
0.04064µm Ra
That's 1.63× as rough as an optical mirror, while a ground surface is 9.8× rougher. A human hair is about 1,722 times that height.
Convert the other way: µm Ra to µin 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 µin Ra to µm Ra
To convert microinches Ra to micrometers Ra, multiply by 0.0254.
Example: 1.6 µin Ra × 0.0254 = 0.04064 µm Ra.
In the other direction, 1 µm Ra = 39.3701 µin Ra.
Every unit
Your roughness in every unit
Tables
µin Ra to µm Ra conversion table
| µin Ra | µm Ra |
|---|---|
| 0.025 µin Ra | 0.000635 µm Ra |
| 0.05 µin Ra | 0.00127 µm Ra |
| 0.1 µin Ra | 0.00254 µm Ra |
| 0.2 µin Ra | 0.00508 µm Ra |
| 0.4 µin Ra | 0.01016 µm Ra |
| 0.8 µin Ra | 0.02032 µm Ra |
| 1.6 µin Ra | 0.04064 µm Ra |
| 3.2 µin Ra | 0.08128 µm Ra |
| 6.3 µin Ra | 0.16002 µm Ra |
| 12.5 µin Ra | 0.3175 µm Ra |
| 25 µin Ra | 0.635 µm Ra |
| 50 µin Ra | 1.27 µm Ra |
µm Ra to µin Ra conversion table
| µm Ra | µin Ra |
|---|---|
| 0.025 µm Ra | 0.984252 µin Ra |
| 0.05 µm Ra | 1.9685 µin Ra |
| 0.1 µm Ra | 3.93701 µin Ra |
| 0.2 µm Ra | 7.87402 µin Ra |
| 0.4 µm Ra | 15.748 µin Ra |
| 0.8 µm Ra | 31.4961 µin Ra |
| 1.6 µm Ra | 62.9921 µin Ra |
| 3.2 µm Ra | 125.984 µin Ra |
| 6.3 µm Ra | 248.031 µin Ra |
| 12.5 µm Ra | 492.126 µin Ra |
| 25 µm Ra | 984.252 µin Ra |
| 50 µm Ra | 1,968.5 µin Ra |
Quick answers
Quick answers
- How many µm Ra is 1 µin Ra?
- 1 µin Ra is 0.0254 µm Ra.
- How many µm Ra is 10 µin Ra?
- 10 µin Ra is 0.254 µm Ra.
- How many µm Ra is 1.6 µin Ra?
- 1.6 µin Ra is 0.04064 µm Ra.
The units
About these units
Microinches Ra (µin Ra)
The US unit. 63 µin is the common machined finish.
Micrometers Ra (µm Ra)
The international standard for average roughness.
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