Test Piece Minimum Thickness for Rockwell Hardness Test
( diamond indenter )
| TEST | ROCKWELL SUPERFICIAL | ROCKWELL | |||||
| SPECIMEN | Diamond "N" Brale Indentor | Diamond Brale Indenter |
|||||
| THICKNESS | HR 15 N | HR 30 N | HR 45 N | HRA | HRD | HRC | |
| inches | mm | 15 kg | 30 kg | 45 kg | 60 kg | 100 kg | 150 kg |
| 0.006 | 0.15 | 92 | N | N | N | N | N |
| 0.008 | 0.2 | 90 | N | N | N | N | N |
| 0.010 | 0.25 | 88 | N | N | N | N | N |
| 0.012 | 0.3 | 83 | 82 | 77 | N | N | N |
| 0.014 | 0.36 | 76 | 80 | 74 | N | N | N |
| 0.016 | 0.41 | 68 | 74 | 72 | 86 | N | N |
| 0.018 | 0.46 | Y | 66 | 68 | 84 | N | N |
| 0.020 | 0.51 | Y | 57 | 63 | 82 | 77 | N |
| 0.022 | 0.56 | Y | 47 | 58 | 78 | 75 | 69 |
| 0.024 | 0.61 | Y | Y | 51 | 76 | 72 | 67 |
| 0.026 | 0.66 | Y | Y | 37 | 71 | 68 | 65 |
| 0.028 | 0.71 | Y | Y | 20 | 67 | 63 | 62 |
| 0.030 | 0.76 | Y | Y | Y | 60 | 58 | 57 |
| 0.032 | 0.81 | Y | Y | Y | Y | 51 | 52 |
| 0.034 | 0.86 | Y | Y | Y | Y | 43 | 45 |
| 0.036 | 0.91 | Y | Y | Y | Y | X | 37 |
| 0.038 | 0.97 | Y | Y | Y | Y | Y | 28 |
| 0.040 | 1.02 | Y | Y | Y | Y | Y | 20 |
