ASTM A540 / A540M Grade B24V Class 1/2/3 Bolting

ASTM A540 / A540M Grade B24v Alloy Steel Heavy Hex Bolts, Stud Bolts.

ASTM A540 Grade B24V is a high tensile alloy steel bolting grade intended for special application such as nuclear power plant installations. Grade B24V Bolts are available in 3 different tensile class namely 3,2 &1 depending upon the diameter of the bolts. A540 Grade B24V bolts are manufactured from Chromium Nickel Molybdenum Vanadium (Cr-Ni-Mo-V) Steel (AISI 4340V-Modified) with tensile ranging from 145 ksi to 165 ksi (inch-pound) & 1000MPa to 1140 Mpa. These bolts need to undergo charpy v notch impact test as compulsory requirement. Ferrobend can produce these bolting from 1/2 inch through 11 inch with EN 10204 Type 3.1 Certification.

ASTM A540 Grade B24V Tensile Class

Grade B24V -- -- Class 3 Class 2 Class 1

ASTM A540 Grade B24V Chemical CompositionA

Element
Grade B24V
4340V-Mod.
Chrome Nickel Moly Vanadium
RangeB, %
Carbon 0.37 - 0.44
Manganese 0.60 - 0.95
PhosphorusC, max 0.025
SulfurC, max 0.025
Silicon 0.15 - 0.35D
Chromium 0.60 - 0.95
Nickel 1.55 - 2.00
Molybdenum 0.40 - 0.60
Vanadium 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 Grade B24V 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 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 Grade B24V 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 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 Grade B24v 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 Grade B24v Hardness Requirement

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 Grade B24v Bolt Marking

Grade Marking
Grade B24V Class 1 B24V-1 BPF
Grade B24V Class 2 B24V-2 BPF
Grade B24V Class 3 B24V-3 BPF