ASTM A453 Grade 660 Class B Fasteners
ASTM A453 Grade 660 Chemical Composition
| Elements | Content, % | Allowable Variation, Over or Under, % |
| Carbon | 0.08 max | 0.01 over |
| Manganese | 2.00 max | 0.04 |
| Phosphorus | 0.04 max | 0.005 over |
| Sulfur | 0.03 max | 0.005 over |
| Silicon | 1.00 max | 0.05 |
| Nickel | 24.00 – 27.00 | 0.20 |
| Chromium | 13.50 – 16.00 | 0.20 |
| Molybdenum | 1.00 – 1.50 | 0.05 |
| Titanium | 1.90 – 2.35 | 0.05 |
| Aluminum | 0.35 max | 0.05 over |
| Vanadium | 0.10 – 0.50 | 0.03 |
| Boron | 0.001 – 0.010 | 0.0004 under to 0.001 over |
ASTM A453 Grade 660 Class B Mechanical Properties
| Tensile Class | Tensile Strength, min | Yield Strength,(0.2% offset), min | Elongation in 4D, min, % | Reduction of Area, min, % | ||
| ksi | Mpa | ksi | Mpa | |||
| B | 130 | 895 | 85 | 585 | 15 | 18 |
ASTM A453 Grade 660 Class B Hardness
| Brinell Hardness Number | Approximate Rockwell Hardness | |
| min | max | |
| 248 - 341 | 24 HRC | 27 HRC |
ASTM A453 Grade 660 Class B Stress Rupture Requirements
| Tensile Class | Test Temperature ºF [ºC] | Stress, min | Time to Rupture, min, h [Note] | Elongation, min, % | |
| ksi | Mpa | ||||
| B | 1200 [650] | 56 | 385 | 100 | 5 |
Note : The combination bar specimen shall be tested continuously at the temperature and at the minimum stress specified or at a greater stress and shall rupture in a time not less than that specified.