| Surface Finish Measurement Comparisons | ||||
| RMS (Micro-inch) |
RMS (Micron) |
Ra (Micro Inch) |
Ra (Micron) |
Typical Equipment Grit Finish |
| 160 | 4.06 | 142 | 3.61 | 36 |
| 98 | 2.49 | 87 | 2.21 | 60 |
| 80 | 2.03 | 71 | 1.80 | 80 |
| 58 | 1.47 | 52 | 1.32 | 120 |
| 47 | 1.20 | 42 | 1.06 | 150 |
| 47 | 1.20 | 42 before Bead Blasting | 1.06 | USDA Bead Blast |
| 34 | 0.86 | 30 | 0.76 | 180 |
| 21 | .053 | 19 | 0.48 | 220 |
| 17 | .43 | 15 | 0.38 | 240 |
| 14 | 0.36 | 12 | 0.30 | 320 |
| 10 | .25 | 9 | 0.23 | 400 |
| 5 | 0.13 | 4 (+/-2) | 0.10 | Mirror |