ASTM F2281 Heat-Resisting and High-Temperature Bolts, Cap Screws and Studs
The commercial high-temperature bolting specification: stainless and nickel-alloy bolts, cap screws and studs for heat-resisting service, from annealed 304 at 75 ksi to aged 718 at 185 ksi, with elevated-temperature properties as a supplementary requirement.
What F2281 is.
ASTM F2281 covers bolts, hex cap screws and studs in heat-resisting and high-temperature alloys for general industrial use outside the pressure codes. Type I is the heat-resisting stainless group: austenitic 304, 304L, 316 and 316L (Class A), martensitic 410, 416 and 431 (Class B) and ferritic 430 (Class C). Type II is the higher-alloy austenitics 309, 310, 321, 330 and 347. Type III is the nickel alloys: 600 and 601 (Class A), A-286 Grade 660 (Class B) and 718 (Class C). Each alloy has conditions and markings, and Supplementary Requirement S8 adds tested elevated-temperature properties.
We machine F2281 bolting from certified bar in every listed alloy, heat treated to the condition ordered, with PMI on the nickel alloys. Where the drawing is a pressure flange, the same alloys are supplied to A193 or A453 instead.
Chemical composition.
| Element | 600 | 660 (A-286) | 718 |
|---|---|---|---|
| Carbon, max | 0.10 | 0.08 | 0.08 |
| Manganese, max | 1.00 | 2.00 | 0.35 |
| Silicon, max | 0.50 | 1.00 | 0.35 |
| Chromium | 14.0–17.0 | 13.5–16.0 | 17.0–21.0 |
| Nickel | 72.0 min | 24.0–27.0 | 50.0–55.0 |
| Molybdenum | — | 1.00–1.75 | 2.80–3.30 |
| Titanium | — | 1.90–2.30 | 0.65–1.15 |
| Aluminium | — | 0.35 max | 0.20–0.80 |
| Niobium + tantalum | — | — | 4.75–5.50 |
| Iron | 6.0–10.0 | balance | balance |
Values per ASTM F2281-04 Table 1 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. The stainless grades match their A276 compositions and are listed in the same table.
Mechanical properties.
| Alloy · condition · marking | Tensile strength, min (ksi) | Yield strength, min (ksi) | Elongation, min (%, machined specimen) | Hardness | — |
|---|---|---|---|---|---|
| 304, 316 · A, CWA, HWA · F1A–F1F | 75 | 30 | 30 | 65–95 HRB | |
| 410, 416 · H · F1G | 110 | 85 | 15 | 20–30 HRC | |
| 410, 416 · HT · F1H | 160 | 120 | 12 | 34–45 HRC | |
| 431 · H · F1I | 125 | 100 | 15 | 25–32 HRC | |
| 431 · HT · F1J | 180 | 140 | 10 | 40–48 HRC | |
| 430 · A · F1K | 55 | 30 | — | 65–95 HRB | |
| 309, 310, 321, 347, 330 · A · F2A, F2D, F2G | 75 | 30 | 30 | 85–95 HRB | |
| 309, 310, 321, 347, 330 · CWA, HWA · F2B, F2C, F2E, F2F, F2H, F2I | 75 | 30 | 30 (20 for CWA of 321, 347, 330) | 65–95 HRB | |
| 600, 601 · A · F3A–F3C | 80 | 25 | 35 | 65–85 HRB | |
| 660 · AH1, AH2, AH3 · F3D–F3F | 130 | 85 | 15 | 22–37 HRC | |
| 718 · AH4 · F3G | 185 | 150 | 12 | 36–48 HRC |
Values per ASTM F2281-04 Table 2 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team.
Specifications that apply.
How F2281 ships from Houston.
- Hex and heavy hex bolts and cap screws
- Studs and threaded rod
- Nuts and washers to match
- Machined specials to drawing
F2281 fasteners we make.
Every item is manufactured to your drawing or standard in F2281, imperial or metric, with an EN 10204 3.1 certificate.
When to order F2281 instead of A193
A193 and A453 are written for pressure-retaining joints and carry the testing and marking those codes require. F2281 covers the same alloys for everything else that runs hot: furnace hardware, exhaust systems, burner and kiln assemblies, turbocharger studs. It adds grades that the pressure specifications do not, such as 309, 310, 330 and 601 for oxidation resistance, and it lets the purchaser order tested elevated-temperature properties through S8. If the joint is on a flange under ASME B31.3 or Section VIII, order A193; if it is a hot bolt anywhere else, F2281 fits.
Testing, certification and marking
- Tensile, yield and hardness per lot; elevated-temperature properties under S8
- Condition marking F1A to F3G and manufacturer's identification on the head
- Certificate of conformance or test report with heat number; EN 10204 3.1 available
- PMI standard on the nickel alloys
ASTM A193 Grade B8 Class 1 (304 Stainless)
304 stainless bolting — Class 1 for corrosion resistance and cryogenic-to-1500 °F service, Class 2 strain hardened to 125 ksi for strength.
ASTM A453 / ASME SA-453ASTM A453 Grade 660 (A-286)
A-286 bolting for the hottest joints — 130 ksi at room temperature and rated by stress-rupture at 1200 °F, for gas and steam turbines, exhaust and high-temperature process equipment.
ASTM B637 bar · AMS 5662 / 5663 · API 6A CRAInconel 718 (UNS N07718)
The premier high-strength nickel superalloy — 185 ksi tensile and 150 ksi yield from cryogenic temperatures to 1200 °F, with corrosion and sour-gas resistance to match.