ASTM A540/A540M - 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.

ASTM 540/A540M Bolting Grades and Classes

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

ASTM A540/A540M Chemical CompositionA

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.

ASTM A540 Mechanical Properties (Imperial)

Grades 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

ASTM A540M Mechanical Properties (Metric)

Grades Class Diameter, mm. 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]
Metric Units
Mpa Mpa In 50 mm Min Max
Grade B21 (Cr-Mo-V) 5 to 50, incl. 825 725 15 50 241 285 D
5 over 50 to 150, incl. 795 690 15 50 248 302 D
5 over 150 to 200, incl. 795 690 15 50 255 311 D
4 to 75, incl. 930 825 13 45 269 331 D
4 over 75 to 150, incl. 930 825 13 45 277 352 D
3 to 75, incl. 1000 895 12 40 293 352 D
3 over 75 to 150, incl. 1000 895 12 40 302 375 D
2 to 100, incl. 1070 965 11 40 311 401 D
1 to 100, incl. 1140 1035 10 35 321 429 D
Grade B22 (4142-H) 5 to 50, incl. 825 725 15 50 248 293 A
5 over 50, to 100, incl. 795 690 15 50 255 302 D
4 to 25, incl. 930 825 13 45 269 341 A
4 over 25 to 100, incl. 930 825 13 45 277 363 D
3 to 50, incl. 1000 895 12 40 293 363 D
3 over 50 to 100, incl. 1000 895 12 40 302 375 D
2 to 75, incl. 1070 965 11 40 311 401 D
1 to 38, incl. 1140 1035 10 35 321 401 D
Grade B23 (E-4340-H) 5 to 50, incl. 825 725 15 50 248 311 A
5 over to 200, incl. 795 690 15 50 255 321 A
5 over 200 to 240, incl. 795 690 15 50 262 321 D
4 to 75, incl. 930 825 13 45 269 341 A
4 over 75 to 150, incl. 930 825 13 45 277 352 A
4 over 150 to 240, incl. 930 825 13 45 285 363 D
3 to 75, incl. 1000 895 12 40 293 363 B
3 over 75 to 150, incl. 1000 895 12 40 302 375 B
3 over 150 to 9-1/2, incl. 1000 895 12 40 311 388 D
2 to 75, incl. 1070 965 11 40 311 388 D
2 over 75 to 150, incl. 1070 965 11 40 311 401 D
2 over 150 to 240, incl. 1070 965 11 40 321 415 D
1 to 75, incl. 1140 1035 10 35 321 415 D
1 over 75 to 150, incl. 1140 1035 10 35 331 429 D
1 over 150 to 200, incl. 1140 1035 10 35 341 444 D
Grade B24 (4340 Mod.) 5 to 50, incl. 825 725 15 50 248 311 A
5 over 150 to 200, incl. 795 690 15 50 255 321 A
5 over 200 to 240,, incl. 795 690 15 50 262 321 A
4 to 75, incl. 930 825 13 45 269 341 A
4 over 75 to 150, incl. 930 825 13 45 277 352 A
4 over 150 to 200, incl. 930 825 13 45 285 363 A
4 over 200 to 240, incl. 930 825 13 45 293 363 D
3 to 75, incl. 1000 895 12 40 293 363 B
3 over 75 to 200, incl. 1000 895 12 40 302 388 B
3 over 200 to 240, incl. 1000 895 12 40 311 388 D
2 to 180, incl. 1070 965 11 40 311 401 B
2 over 180 to 240, incl. 1070 965 11 40 321 415 D
1 to 150, incl. 1140 1035 10 35 321 415 C
1 over 150 to 200, incl. 1140 1035 10 35 331 429 D
Grade B24V (4340V Mod.) 3 to 100, incl. 1000 130 12 40 293 363 A
3 over 100 to 200, incl. 1000 130 12 40 302 375 B
3 over 200 to 280, incl. 1000 130 12 40 311 388 C
2 to 100, incl. 1070 140 11 40 311 388 B
2 over 100 to 200, incl. 1070 140 11 40 311 401 C
2 over 200 to 280, incl. 1070 140 11 40 321 415 D
1 to 100, incl. 1140 150 10 35 321 415 C
1 over 100 to 200, incl. 1140 150 10 35 331 429 D
1 over 200 to 280, incl. 1140 150 10 35 331 444 D

Note A : The minimum average of 3 specimens shall not be less than 35ft-lbf (47 J). One specimen from a set of 3 may be less than 35 ft-lbf (47 J) but not less than 30 ft-lbf (41J).

Note B : The minimum average of 3 specimens shall not be less than 30ft-lbf (41 J). One specimen from a set of 3 may be less than 30 ft-lbf (41 J) but not less than 25 ft-lbf (34J).

Note C : The minimum average of 3 specimens shall not be less than 25ft-lbf (34 J). One specimen from a set of 3 may be less than 25 ft-lbf (34 J) but not less than 20 ft-lbf (27J).

Note D : No minimum values established. Tests shall be run for information only.

ASTM A540/A540M Heat Treatment

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.

ASTM A540/A540M Bolting Hardness Requirements

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.

ASTM A540/A540M Bolting Marking

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.