ASTM A540 - Standard specification for Alloy Steel Bolting for Special Applications
This specification covers 5 grades of bolting with twelve classes of yield strength ranging from 50 to 120 ksi [345 to 827 Mpa] for used in high temperature service such as fasteners for pressure bessel and valve flanges. The specification is expressed in both inch-pound units and in SI units. BoltPort primarily stocks and supply A453 Grade 660 Boltings for high temperature service. We stock round bar in Grade 660, Grade 651 & Grade 665 for quick manufacturing these bolts. These bolts are solution annealed and age hardened to provide maximum efficiency in their applications. We offer Rupture Test Facility for sufficient quantity order.
| Type | Tensile Class | ||||
|---|---|---|---|---|---|
| Grade B21 | Class 5 | Class 4 | Class 3 | Class 2 | Class 1 |
| Grade B22 | Class 5 | Class 4 | Class 3 | Class 2 | Class 1 |
| Grade B23 | Class 5 | Class 4 | Class 3 | Class 2 | Class 1 |
| Grade B24 | Class 5 | Class 4 | Class 3 | Class 2 | Class 1 |
| Grade B24V | -- | -- | Class 3 | Class 2 | Class 1 |
| Element | Grade B21 | Grade B22 | Grade B23 | Grade B24 | Grade B24V |
|---|---|---|---|---|---|
| Cr-Mo-V | 4142-H | E-4340-H | 4340-Mod. | 4340V-Mod. | |
| Chrome Moly Vanadium | Chrome Moly | Chrome Nickel Vanadium | Chrome Nickel Vanadium | Chrome Nickel Moly Vanadium | |
| RangeB, % | |||||
| Carbon | 0.35 - 0.44 | 0.39 - 0.46 | 0.37 - 0.44 | 0.37 - 0.44 | 0.37 - 0.44 |
| Manganese | 0.45 - 0.70 | 0.65 - 1.10 | 0.60 - 0.95 | 0.70 - 0.90 | 0.60 - 0.95 |
| PhosphorusC, max | 0.025 | 0.025 | 0.025 | 0.025 | 0.025 |
| SulfurC, max | 0.025 | 0.025 | 0.025 | 0.025 | 0.025 |
| Silicon | 0.15 - 0.35 | 0.15 - 0.35 | 0.15 - 0.35 | 0.15 - 0.35 | 0.15 - 0.35D |
| Chromium | 0.80 - 1.15 | 0.75 - 1.20 | 0.65 - 0.95 | 0.70 - 0.95 | 0.60 - 0.95 |
| Nickel | -- | -- | 1.55 - 2.00 | 1.65 - 2.00 | 1.55 - 2.00 |
| Molybdenum | 0.50 - 0.65 | 0.15 - 0.25 | 0.20 - 0.30 | 0.30 - 0.40 | 0.40 - 0.60 |
| Vanadium | 0.25 - 0.35 | --- | --- | --- | 0.04 - 0.10 |
A The intensional addition of Bi, Se, Te and Pb is not permitted.
B Unless otherwise specified, separate determinations may vary from the specified ranges, except that elements in any heat mush not vary both above and below the specified range.
C Phosphorus and sulfur content is 0.04% max when open hearth steel is specified.
D Silicon content is 0.35& mac if vacuum carbon deoxidized.
| Types | Class | Diameter, inch. | Tensile Strength, min | Yield Strength, 0.2% offset, min |
Elongation min, % |
Reduction of Area, min, % |
Surface Brinell Hardness |
Charpy V Notch +10 °F [-12.2 °C] | |
|---|---|---|---|---|---|---|---|---|---|
| Inch Pound Units | |||||||||
| ksi | ksi | In 2 inch. | Min | Max | |||||
| Grade B21 (Cr-Mo-V) | 5 | to 2, incl. | 120 | 105 | 15 | 50 | 241 | 285 | D |
| 5 | over 2 to 6, incl. | 115 | 100 | 15 | 50 | 248 | 302 | D | |
| 5 | over 6 to 8, incl. | 115 | 100 | 15 | 50 | 255 | 311 | D | |
| 4 | to 3, incl. | 135 | 120 | 13 | 45 | 269 | 331 | D | |
| 4 | over 3 to 6, incl. | 135 | 120 | 13 | 45 | 277 | 352 | D | |
| 3 | to 3, incl. | 145 | 130 | 12 | 40 | 293 | 352 | D | |
| 3 | over 3 to 6, incl. | 145 | 130 | 12 | 40 | 308 | 375 | D | |
| 2 | to 4, incl. | 155 | 140 | 11 | 40 | 311 | 401 | D | |
| 1 | to 4, incl. | 165 | 150 | 10 | 35 | 321 | 429 | D | |
| Grade B22 (4142-H) | 5 | to 2, incl. | 120 | 105 | 15 | 50 | 248 | 293 | A |
| 5 | over 2 to 4, incl. | 115 | 100 | 15 | 50 | 255 | 302 | D | |
| 4 | to 1, incl. | 135 | 120 | 13 | 45 | 269 | 341 | A | |
| 4 | over 1 to 4, incl. | 135 | 120 | 13 | 45 | 277 | 363 | D | |
| 3 | to 2, incl. | 145 | 130 | 12 | 40 | 293 | 363 | D | |
| 3 | over 2 to 4, incl. | 145 | 130 | 12 | 40 | 302 | 375 | D | |
| 2 | to 3, incl. | 155 | 140 | 11 | 40 | 311 | 401 | D | |
| 1 | to 1-1/2, incl. | 165 | 150 | 10 | 35 | 321 | 401 | D | |
| Grade B23 (E-4340-H) | 5 | to 6, incl. | 120 | 105 | 15 | 50 | 248 | 311 | A |
| 5 | over to 8, incl. | 115 | 100 | 15 | 50 | 255 | 321 | A | |
| 5 | over 8 to 9-1/2, incl. | 115 | 100 | 15 | 50 | 262 | 321 | D | |
| 4 | to 3, incl. | 135 | 120 | 13 | 45 | 269 | 341 | A | |
| 4 | over 3 to 6, incl. | 135 | 120 | 13 | 45 | 277 | 352 | A | |
| 4 | over 6 to 9-1/2, incl. | 135 | 120 | 13 | 45 | 285 | 363 | D | |
| 3 | to 3, incl. | 145 | 130 | 12 | 40 | 293 | 363 | B | |
| 3 | over 3 to 6, incl. | 145 | 130 | 12 | 40 | 302 | 375 | B | |
| 3 | over 6 to 9-1/2, incl. | 145 | 130 | 12 | 40 | 311 | 388 | D | |
| 2 | to 3, incl. | 155 | 140 | 11 | 40 | 311 | 388 | D | |
| 2 | over 3 to 6, incl. | 155 | 140 | 11 | 40 | 311 | 401 | D | |
| 1 | to 3, incl. | 165 | 150 | 10 | 35 | 321 | 415 | D | |
| 1 | over 3 to 6, incl. | 165 | 150 | 10 | 35 | 331 | 429 | D | |
| 1 | over 6 to 8, incl. | 165 | 150 | 10 | 35 | 341 | 444 | D | |
| Grade B24 (4340 Mod.) | 5 | to 6, incl. | 120 | 105 | 15 | 50 | 248 | 311 | A |
| 5 | over 6 to 8, incl. | 115 | 100 | 15 | 50 | 255 | 321 | A | |
| 5 | over 8 to 9-1/2, incl. | 115 | 100 | 15 | 50 | 262 | 321 | A | |
| 4 | to 3, incl. | 135 | 120 | 13 | 45 | 269 | 341 | A | |
| 4 | over 3 to 6, incl. | 135 | 120 | 13 | 45 | 277 | 352 | A | |
| 4 | over 6 to 8, incl. | 135 | 120 | 13 | 45 | 285 | 363 | A | |
| 4 | over 8 to 9-1/2, incl. | 135 | 120 | 13 | 45 | 293 | 363 | D | |
| 3 | to 3, incl. | 145 | 130 | 12 | 40 | 293 | 363 | B | |
| 3 | over 3 to 8, incl. | 145 | 130 | 12 | 40 | 302 | 388 | B | |
| 3 | over 8 to 9-1/2, incl. | 145 | 130 | 12 | 40 | 311 | 388 | D | |
| 2 | to 7, incl. | 155 | 140 | 11 | 40 | 311 | 401 | B | |
| 2 | over 7 to 9-1/2, incl. | 155 | 140 | 11 | 40 | 321 | 415 | D | |
| 1 | to 6, incl. | 165 | 150 | 10 | 35 | 321 | 415 | C | |
| 1 | over 6 to 8, incl. | 165 | 150 | 10 | 35 | 331 | 429 | D | |
| Grade B24V (4340 Mod.) | 3 | to 4, incl. | 145 | 130 | 12 | 40 | 293 | 363 | A |
| 3 | over 4 to 8, incl. | 145 | 130 | 12 | 40 | 302 | 375 | B | |
| 3 | over 8 to 11, incl. | 145 | 130 | 12 | 40 | 311 | 388 | C | |
| 2 | to 4, incl. | 155 | 140 | 11 | 40 | 311 | 388 | B | |
| 2 | over 4 to 8, incl. | 155 | 140 | 11 | 40 | 311 | 401 | C | |
| 2 | over 8 to 11, incl. | 155 | 140 | 11 | 40 | 321 | 415 | D | |
| 1 | to 4, incl. | 165 | 150 | 10 | 35 | 321 | 415 | C | |
| 1 | over 4 to 8, incl. | 165 | 150 | 10 | 35 | 331 | 429 | D | |
| 1 | over 8 to 11, incl. | 165 | 150 | 10 | 35 | 331 | 444 | D | |
Bolting material ordered in the annealed condition shall have a structure suitable for machining. Such annealed material is not intended to be used without subsequent quenching and tempering. Bolting ordered in the liquid quenched and tempered condition shall be uniformly reheated froma temperature below the cooling transformation range to the proper austenitizing temperature, quenched in a liquid medium under substantially uniform conditions, and then uniformly reheated for tempering. The minimum tempering tempereture shall be 850°F [455°C].
Material that has been straintened after quenching and tempering shall be stress relieved by reheating to a temperature not lower than 100°F [55°C] under the tempering temperature.
The hardness shall be determined on the surface of the material removal of decarburization. The hardness of material in the annealed condition shall not be greater than 235 HB. The hardness of material in the quenched and tempered or quenched, temepred and stress-relieved condition shall be within the limits in hardness column of the mechanical properties table.
Grade and manufacturer's identification symbols shall be applied to one end of studs and to the heads of bolts of all sizes. If the available area is inadequate, the grade symbol may be marked on one end and the manufacturer's identification symbol marked on the other end.