Understanding bolt strength grades and their correct applications
| Grade | Min Tensile (MPa) | Yield (MPa) | Marking |
|---|---|---|---|
| 4.6 | 400 | 240 | 4.6 |
| 5.8 | 500 | 400 | 5.8 |
| 8.8 | 800 | 640 | 8.8 |
| 10.9 | 1000 | 900 | 10.9 |
| 12.9 | 1200 | 1080 | 12.9 |
Grade 2: low carbon. Grade 5: medium carbon, 120ksi. Grade 8: medium alloy, 150ksi. Markings: radial lines on head.