 |
Ra = Roughness Average
On a microscopic level, stainless steel is not perfectly
smooth. Ra indicates the average distance between the peaks and
valleys of the surface. Measured in micro-inches (millionths
of an inch).Also measured in Grit which measures the texture
of the surface.For roughness average, the lower the value the
smoother the finish. Conversly, when reading grit, the higher
the value, the smoother the finish.
| Basic Sheet Designation |
Grit Size |
Ra |
| #2B |
-- |
50 |
| -- |
150 |
30 |
| #4 |
180 |
20 |
| #6 |
240 |
16 |
| #8 |
320 |
10 |
| -- |
400 |
7 |
| -- |
600 |
5 |
|
