Minimum Thickness of Test Piece
for Rockwell Hardness Testing ( Ball Indenters )
| TEST | ROCKWELL SUPERFICIAL | ROCKWELL | |||||
| SPECIMEN | 1/16" Ball Indentor | 1/16" Ball Indentor | |||||
| THICKNESS | HR 15 T | HR 30 T | HR 45 T | HRF | HRB | HRG | |
| inches | mm | 15 kg | 30 kg | 45 kg | 60 kg | 100 kg | 150 kg |
| 0.005 | 0.13 | 93 | N | N | N | N | N |
| 0.010 | 0.25 | 90 | 87 | N | N | N | N |
| 0.015 | 0.38 | 78 | 77 | 77 | N | N | N |
| 0.020 | 0.51 | Y | 58 | 62 | 100 | N | N |
| 0.025 | 0.63 | Y | Y | 26 | 92 | 92 | 90 |
| 0.030 | 0.76 | Y | Y | Y | 67 | 68 | 69 |
| 0.035 | 0.89 | Y | Y | Y | Y | 44 | 46 |
| 0.040 | 1.02 | Y | Y | Y | Y | 20 | 22 |
