This F2281 specification covers the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs, 1⁄4 in. diameter and larger, intended for use at temperatures up to 1800°F (982°C), and in applications where resistance to heat and the effects of high temperature are to be considered. A wide variety of materials are covered in this specification which can be used at high temperatures as a function of the specific alloy properties, as well as environmental requirements including corrosive environments.
Three types of material, are covered in this specification and are classified into the following:
| Alloy Grade | UNS Designation |
|---|---|
| 304 | S30400 |
| 304L | S30403 |
| 316 | S31600 |
| 316L | S31603 |
| Alloy Grade | UNS Designation |
|---|---|
| 410 | S41000 |
| 416 | S41600 |
| 431 | S43100 |
| Alloy Grade | UNS Designation |
|---|---|
| 430 | S43000 |
| 430F | S43020 |
| Alloy Grade | UNS Designation |
|---|---|
| 309 | S30900 |
| 310 | S31000 |
| 321 | S32100 |
| 330 | N08330 |
| 347 | S34700 |
| Alloy Grade | UNS Designation |
|---|---|
| 600 | N06600 |
| 601 | N06601 |
| Alloy Grade | UNS Designation |
|---|---|
| 660 | S66286 |
| Alloy Grade | UNS Designation |
|---|---|
| 718 | N07718 |
Specifications A276, A484, A493, A564/A564M, A582/A 582M, B637 are noted for information only as suitable sources of material for the manufacture of bolts, hex cap screws, and studs to this specification.
The bolts, hex cap screws, and studs shall be manufactured from material having a chemical composition conforming to the requirements listed in Table 1 and capable of developing the mechanical property requirements listed in Table 2 for the finished fastener.
Various grades of material having unique heat resisting or high temperature characteristics are specified in this specification. A guide to their application is listed to assist in the selection of the fastener material.
The form and condition of the raw material shall be at the option of the manufacturer but shall be such that the finished fastener conforms to all the specified requirements.
Forming—Unless otherwise specified, the fasteners shall be cold formed, hot formed, or machined from suitable material, at the option of manufacturer.
Threads—Unless otherwise specified, the threads shall be rolled or cut, at the option of the manufacturer.
Condition—The fasteners shall be furnished in one of the following conditions and shall be agreed upon between the manufacturer and the purchaser at the time of the inquiry and order.
| Type | Class | Condition |
|---|---|---|
| I | A | A, CWA, HWA |
| I | B | H, HT |
| I | C | A, CWA, HWA |
| II | ... | A, CWA, HWA |
| III | A | A, CWA, HWA |
| III | B | AH1, AH2 or AH3 |
| III | C | AH4 |
| Condition A | Machined from annealed or solution-annealed stock thus retaining the properties of the original material | |
| CWA | Cold formed from annealed or solution-annealed stock and then re-annealed | |
| HWA | Hot formed from annealed or solution-annealed stock and then re-annealed | |
| H | Hardened and tempered at 1050°F (565°C) minimum | |
| HT | Hardened and tempered at 525°F (274°C) minimum | |
| AH1 | Solution Treated at 1850°F (1010°C) and Precipitation Hardened (Aging) | |
| AH1 | Solution Treated at 1850°F (1010°C) and Precipitation Hardened (Aging) | |
| AH2 | Solution Treated at 1700°F (927°C) and Precipitation Hardened (Aging) | |
| AH3 | Solution Treated at 1850°F (1010°C) and Double Aged | |
| AH4 | Solution Treated at 1725°F (941°C) to 1850°F (1010°C) and Precipitation Hardened (Aging) | |
Chemical Composition—Bolts, hex cap screws, and studs shall conform to the chemical composition requirements prescribed in Table 1 for the specified alloy grade.
Product Analysis:
When a product analysis is made by the purchaser
from finished fasteners representing each lot, the chemical
composition thus determined shall conform to the requirements
listed in Table 1 for the specified alloy grade, subject to the
Product Analysis tolerance listed in Specifications A484 and
B880.
In the event of a discrepancy, a referee chemical analysis of samples, taken from each lot, shall be made in accordance with 14.1 and 15.1.
| Composition, % maximum except as shown | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Alloy | Carbon | Mang. | Phos. | Sulfur | Silicon | Chromium | Nickel | Copper | Moly | Other |
| Type I, Class A, Heat Resisting Austenitic Grades | ||||||||||
| 304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0/20.0 | 8.0/10.5 | 1.00 | ||
| 304L | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0/20.0 | 8.0/12.5 | 1.00 | ||
| 316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0/18.0 | 10.0/14.0 | 2.00/3.00 | ||
| Type I, Class B, Heat Resisting Martensitic Grades | ||||||||||
| 410 | 0.15 | 1.00 | 0.040 | 0.030 | 1.00 | 11.5/13.5 | ||||
| 416 | 0.15 | 1.25 | 0.060 | 0.15 min | 1.00 | 12.0/14.0 | 0.60 | |||
| 431 | 0.20 | 1.00 | 0.040 | 0.030 | 1.00 | 15.0/17.0 | 1.25/2.50 | |||
| Type1, Class C, Heat Resisting Ferritic Grades | ||||||||||
| 430 | 0.12 | 1.00 | 0.040 | 0.030 | 1.00 | 16.0/18.0 | ||||
| 430F | 0.12 | 1.25 | 0.060 | 0.15 min | 1.00 | 16.0/18.0 | 0.60 | |||
| Type II, Heat Resisting Austenitic Grades | ||||||||||
| 309 | 0.20 | 2.00 | 0.045 | 0.030 | 1.00 | 22.0/24.0 | 12.0/15.0 | |||
| 310 | 0.25 | 2.00 | 0.045 | 0.030 | 1.50 | 24.0/26.0 | 19.0/22.0 | |||
| 321 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0/19.0 | 9.0/12.0 | Ti6XCmin | ||
| 330 | 0.08 | 2.00 | 0.030 | 0.75/150 | 17.0/20.0 | 34.0/37.0 | ||||
| 347 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0/19.0 | 9.0/13.0 | Cb+Ta10XCmin | ||
| Type III, Class A, High Temperature, Nickel Alloy Grades | ||||||||||
| 600 | 0.10 | 1.00 | 0.015 | 0.50 | 14.0/17.0 | 72.0 min | 0.50 | Fe 6.0/10.0 | ||
| 601 | 0.10 | 1.00 | 0.015 | 0.50 | 21.0/25.0 | 58.0/63.0 | 1.00 | AI 1.0/1.7 Fe Remainder |
||
| Type III, Class B, High Temperature, Precipitation Hardened Grade | ||||||||||
| 660 | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 13.5/16.0 | 24.0/27.0 | 1.00/1.75 | Ti 1.90/2.30 V 0.10/0.50 AI 0.35 max B 0.003/0.010 Fe Remainder |
|
| Type III, Class C, High Temperature, Precipitation Hardened Grade | ||||||||||
| 718 | 0.08 | 0.35 | 0.015 | 0.015 | 0.35 | 17.0/21.0 | 50.0/55.0 | 0.30 | 2.80/3.30 | Ti 0.65/1.15 Co 1.00 max AI 0.20/0.80 b 0.000 max Cb + Ta 4.75/5.50 Fe Remainder |
Condition A—(Austenitic Alloys Type I Class A and Type II ), shall be heated to 1850 to 1950°F (1010 to 1066°C),held for a sufficient time, then cooled at a rate sufficient to prevent the precipitation of carbides and to provide the specified properties.
Condition A—(Ferritic Alloys Type I Class C), shall be heated to 1400 to 1500°F (760 to 816°C), held for a sufficient time, and then air cooled to provide the specified properties.
Condition A—(Nickel Alloy Type III Class A), shall be heated to 1600° to 1800°F (871 to 982°C), held for ten to fifteen minutes, and either water quenched or air cooled.
Condition CWA—(Austenitic Alloys Type I Class A and Type II), shall be cold formed from annealed or solution annealed stock and then re-annealed or re-solution annealed in accordance with 6.2.4.1 after all cold working (including heading and threading) has been completed.
Condition CWA—(Ferritic Alloys Type I Class C), shall be cold formed from annealed or solution annealed stock and then re-annealed or re-solution annealed in accordance with 6.2.4.2 after all cold working (including heading and threading) has been completed.
Condition CWA—(Nickel Alloy Type III Class A), shall be cold formed from annealed stock and then re-annealed in accordance with 6.2.4.3 after all cold working (including heading and threading) has been completed.
Condition HWA—(Austenitic Alloys Type I Class A and Type II), shall be hot formed from annealed or solutionannealed stock and then re-annealed or re-solution annealed in accordance with 6.2.4.1 after all hot forming has been completed.
Condition HWA—(Ferritic Alloys Type I Class C), shall be hot formed from annealed or solution-annealed stock and then re-annealed or re-solution annealed in accordance with 6.2.4.2 after all hot forming has been completed.
Condition HWA—(Nickel Alloy Type III Class A), shall be hot formed from annealed or solution-annealed stock and then re-annealed or re-solution annealed in accordance with 6.2.4.3 after all hot forming has been completed.
Condition H—(Martensitic Alloys Type I Class B), shall be hardened by heating to 1800 to 1900°F (982 to 1038°C), held for at least 1⁄2 h and rapid air or oil quenched, then reheated to 1050°F (565°C) minimum for at least 1 h and air cooled to provide the specified properties.
Condition HT—(Martensitic Alloys Type 1 Class B), shall be hardened by heating to 1800 to 1900°F (982 to 1038°C), held for at least 1⁄2 h and rapid air or oil quenched, then reheated to 525°F (274°C) minimum for at least 1 h and air cooled to provide the specified properties.
Condition AH1—(Precipitation Hardened Alloy Type III Class B), shall be solution treated at 1800 to 1900°F (982 to 1038°C), held for 1 h at heat, then cooled rapidly. Precipitation Hardening (Aging) shall be performed by heating to 1300 to 1400°F (704 to 760°C), holding for 12 to 16 h at heat then air cooled. See Note 1.
Condition AH2—(Precipitation Hardened Alloy Type III Class B), shall be solution treated at 1650 to 1750°F (899 to 954°C), held for 2 h at heat, then cooled rapidly. Precipitation Hardening (Aging) shall be performed by heating to 1300 to 1400°F (704 to 760°C), holding for 12 to 16 h at heat then air cooled. See Note 1.
Condition AH3—(Precipitation Hardened Alloy Type III Class B), shall be solution treated at 1800 to 1900°F (982 to 1038°C), held for 1 h at heat, then cooled rapidly. Precipitation Hardening (Aging) shall be performed by heating to 1425 ±25°F (775 ±14°C) holding for 16 h at heat then air cooled. Heated again to 1200 ±25°F (650 ±14°C) holding for 16 h at heat then air cooled.
Condition AH4—(Precipitation Hardened Alloy Type III Class C), shall be solution treated at 1725°F (941°C) to 1850°F (1010°C), held at the selected temperature for a time commensurate with cross-sectional thickness, and cooled at a rate equivalent to an air cool or faster. Solution treating temperatures shall be controlled in a range of ±25°F (±14°C). Precipitation Hardening (Aging) shall be performed by heating to 1325°F (718°C) held at heat for 8 h, cooled to 1150°F (621°C) at a rate of 100°F (56°C) per hour, held for 8 h at heat and air cooled. Alternatively, parts may be furnace cooled to 1150°F (621°C) at any rate provided the time at 1150°F (621°C) is adjusted so the total heat treat time is 18 hminimum. Precipitation treatment temperatures and cooling rates shall be controlled in the range of 615°F (±`8°C).
Bolts, hex cap screws, and studs shall meet the applicable mechanical properties listed in Table 2 for the specified alloy grade and condition when tested at room temperature, in accordance with the mechanical properties requirements specified herein for the type, grade, diameter, and length.
Mechanical Test Requirements:
8.2.1 Bolts and hex cap screws which meet the minimum
requirements for length, and have a maximum 160 000 pound
tensile load, shall have a full size wedge tensile strength and
yield strength test performed as outlined in Section 15. For
bolts and hex cap screws which exceed the 160 000 pound
limit, a Machined Specimen tensile strength, yield strength,
and elongation test performed as outlined in Section 15 may be
substituted for the full size wedge test. In addition, for bolts
and hex cap screws that are less than the minimum length
requiring tension tests, either a full size wedge tensile strength
test, full size axial tensile strength test or a Rockwell hardness
test shall be required as outlined in Section 15. In all cases, full
size wedge tensile strength testing shall be performed whenever
possible.
Studs which meet the minimum requirements for length and have a maximum 160 000 pound tensile load, shall have a full size axial tensile strength test and yield strength test performed as outlined in Section 15. For studs which exceed the 160 000 pound limit, a Machined Specimen tensile strength, yield strength, and elongation test performed as outlined in Section 15 may be substituted for the full size axial test. In addition, for studs that are less than the minimum length requiring tension tests, either a full size axial tensile strength test or a Rockwell hardness test shall be required as outlined in Section 15. In all cases, full size axial tensile strength testing shall be performed whenever possible.
In the event of a discrepancy between full size wedge test, full size axial test, machined specimen test, and Rockwell hardness test results, the precedence sequence shall be the same as the sequence listed in this section for acceptance purposes. That is, if parts pass axial tensile but fail Rockwell hardness they are acceptable; however, if they fail axial tensile and pass Rockwell hardness they are not acceptable.
If tests to determine high temperature properties are required on Type III High Temperature Alloys, supplementary requirement S8 shall be specified in the inquiry and order and high temperature testing shall be performed and meet the applicable mechanical properties listed in Table 3.
| Alloy Grades | Condition | Marking | Nominal Diameters, in. | Full-size Tests | Rockwell Hardness | Machined Specimen Tests | |||
|---|---|---|---|---|---|---|---|---|---|
| Tensile strength, min, ksi | Yeild Strength, min, ksi | Tensile strength, min, ksi | Yeild Strength, min, ksi | Elongation 4D, min % | |||||
| Type I, Class A, Heat Resisting Austenitic Grades | |||||||||
| 304, 304L | A | F1A | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 |
| CWA | F1B | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| HWA | F1C | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| 316, 316L | A | F1D | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 |
| CWA | F1E | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| HWA | F1F | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| Type I, Class B, Heat Resisting Martensitic Grades | |||||||||
| 410, 416F | H | F1G | Up to 4 Diameters | 110 | 85 | 20 to 30 HRC | 110 | 85 | 15 |
| HT | F1H | Up to 4 Diameters | 160 | 120 | 34 to 45 HRC | 160 | 120 | 12 | |
| 431 | H | F1L | All Diameters | 125 | 100 | 25 to 32 HRC | 125 | 100 | 15 |
| HT | F1J | All Diameters | 180 | 140 | 40 to 48 HRC | 180 | 140 | 10 | |
| Type I, Class C, Heat Resisting Ferritic Grades | |||||||||
| 430, 430F | A | F1K | All Diameters | 55 | 30 | 65 TO 95 HRB | 50 | 25 | -- |
| CWA | F1L | All Diameters | 55 | 30 | 65 to 95 HRB | 50 | 25 | -- | |
| HWA | F1M | All Diameters | 55 | 30 | 65 to 95 HRB | 50 | 25 | -- | |
| Type II, Class A Heat Resisting Austenitic Grades | |||||||||
| 309,310 | A | F2A | All Diameters | 75 | 30 | 85 to 95 HRB | 75 | 30 | 30 |
| CWA | F2B | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| HWA | F2C | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| 321,347 | A | F2D | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 |
| CWA | F2E | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 20 | |
| HWA | F2F | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| 330 | A | F2G | All Diameters | 75 | 30 | 85 to 95 HRB | 75 | 30 | 30 |
| CWA | F2H | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 20 | |
| HWA | F2I | All Diameters | 75 | 30 | 65 to 95 HRB | 75 | 30 | 30 | |
| Type III, Class A, High Temperature, Nickel Alloy Grades | |||||||||
| 660, 601 | A | F3A | All Diameters | 80 | 30 | 65 to 85 HRB | 75 | 25 | 35 |
| CWA | F3B | All Diameters | 75 | 30 | 65 to 85 HRB | 75 | 25 | 35 | |
| HWA | F3C | All Diameters | 80 | 25 | 65 to 85 HRB | 75 | 25 | 35 | |
| Type III, Class B, High Temperature, Precipitation Hardened Grade | |||||||||
| 660 | AH1 | F3D | All Diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 |
| AH2 | F3E | All Diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 | |
| AH3 | F3F | All Diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 | |
| Note: Condition AH1 results in increased rupture strength after aging, while Condition AH2 results in better ductility and higher hardness. | |||||||||
| Type III, Class C High Temperature, Precipitation Hardened Grade | |||||||||
| 718 | AH4 | F3G | All Diameters | 185 | 150 | 36 to 48 HRC | 180 | 150 | 12 |
| Temperature | Tensile Strength, ksi |
Yeild 0.2% Strength, ksi |
Elongation in 2 in., % |
|
|---|---|---|---|---|
| °F | °C | |||
| Class A—Nickel Based Alloys Alloy Grade 600 Annealed at 1600°F (871°C) | ||||
| 600 | 316 | 89.0 | 34.0 | 45.0 |
| 1000 | 538 | 82.0 | 33.0 | 42.0 |
| 1400 | 760 | 37.0 | 26.0 | 70.0 |
| 1800 | 982 | 11.0 | 5.0 | 115.0 |
| Alloy Grade 601 Annealed at 1800°F (982°C) | ||||
| 800 | 427 | 104.0 | 54.5 | 36.0 |
| 1000 | 538 | 94.8 | 54.5 | 34.0 |
| 1200 | 649 | 73.5 | 46.5 | 32.0 |
| 1400 | 760 | 37.3 | 36.6 | 88.0 |
| 1800 | 982 | 8.7 | 7.5 | 173.0 |
| Class B—Precipitation Hardened Alloys Alloy Grade 660 | ||||
| 800 | 427 | 138.0 | 93.0 | 18.0 |
| 1000 | 538 | 131.0 | 87.5 | 18.0 |
| 1100 | 593 | 122.0 | 90.0 | 21.0 |
| 1200 | 649 | 104.0 | 88.0 | 13.0 |
| 1300 | 704 | 86.5 | 86.0 | 11.0 |
| 1400 | 760 | 64.0 | 62.0 | 18.0 |
| 1500 | 816 | 36.5 | 33.0 | 68.0 |
| Class C—Precipitation Hardened Alloys Alloy Grade 718 | ||||
| 600 | 316 | 184.0 | 156.0 | 20.0 |
| 1000 | 538 | 173.0 | 148.0 | 16.0 |
| 1200 | 649 | 145.0 | 125.0 | 12.0 |
| 1400 | 760 | 124.0 | 116.0 | 5.0 |
Carbide Precipitation:
The type I, class A austenitic alloys listed in 4.1.1.1 and all type II austenitic
alloys listed in 4.1.2 shall be capable of passing the test for susceptibility to
intergranular corrosion in accordance with Practice E of Practices A 262. 9.1.2 As stated in Practices A
262, samples may be subjected to the faster and more severe screening test in accordance with Practice A.
Failing Practice A, specimens may be tested in accordance with Practice E and be considered satisfactory
if passing Practice E.
Bolts and Hex Cap Screws:
Studs:
Stud Type:
Threads—Unless otherwise specified, studs shall have Class 2A threads in accordance with ASME B1.1.
Points—Unless otherwise specified, the points shall be flat and chamfered or rounded at the option of the manufacturer.
ASTM Standards:
A262 Practices for Detecting Susceptibility to Intergranular
Attack in Austenitic Stainless Steels.
A276 Specification for Stainless Steel Bars and Shapes.
A 342/A342M Test Methods for
Permeability of Feebly Magnetic Materials.
A380 Practice for Cleaning, Descaling, and Passivation of
Stainless Steel Parts, Equipment, and Systems.
A484/
A484M Specification for General Requirements for Stainless
Steel Bars, Billets, and Forgings.
A493 Specification for Stainless Steel Wire and Wire Rods for Cold Heading and Cold
Forging.
A564/A564M
Specification for Hot-Rolled and Cold- Finished Age-Hardening Stainless Steel Bars and
Shapes.
A582/A582M
Specification for Free-Machining Stainless Steel Bars.
A751 Test Methods, Practices, and Terminology for Chemical
Analysis of Steel Products.
B637 Specification for Precipitation-Hardening Nickel Alloy Bars, Forgings, and Forging
Stock for High-Temperature Service.
B880 Specification for General Requirements for Chemical Check
Analysis Limits for Nickel, Nickel Alloys, and Cobalt Alloys.
D3951 Practice for Commercial Packaging
E21 Test Methods for Elevated Temperature Tension Tests of Metallic Materials.
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with
Specifications.
E76 Test Methods for Chemical Analysis of Nickel-Copper Alloys.
E139 Test Methods for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of
Metallic Materials.
E292Test Methods for Conducting Time-for-Rupture Notch Tension Tests of Materials.
E353 Test Methods for Chemical Analysis of Stainless, Heat-Resisting, Maraging, and Other
Similar Chromium-Nickel-Iron Alloys.
E354 Test Methods for Chemical Analysis of High-Temperature, Electrical, Magnetic, and
Other Similar Iron, Nickel, and Cobalt Alloys.
F606 Test Methods for Determining the Mechanical Properties of
Externally and Internally Threaded Fasteners, Washers, and Rivets.
F788/F788M Specification for Surface Discontinuities of Bolts, Screws, and Studs, Inch and
Metric
Series.
F1470 Guide for Fastener Sampling for Specified Mechanical
Properties and Performance Inspection.