Ni-Fe-Cr alloy fasteners – excellent SCC & acid resistance
Service from cryogenic to 1300°F (700°C)
Age-hardenable grades (925/A‑286) for high strength
Sour gas compliant (NACE MR0175) & multiple product forms
Incoloy fasteners are high-performance nickel-iron-chromium alloy bolts, nuts, studs, screws, and washers designed for demanding applications requiring exceptional corrosion resistance, high-temperature strength, and reliability in aggressive environments .
The Incoloy family of alloys offers a range of solutions tailored to specific service conditions. Incoloy 800/800H/800HT fasteners provide outstanding oxidation and carburization resistance at elevated temperatures up to 1100°F (593°C) and beyond . Incoloy 825 fasteners deliver superior resistance to sulfuric acid, phosphoric acid, and chloride-induced stress corrosion cracking . Incoloy 925 fasteners are age-hardenable for high-strength sour gas service, fully compliant with NACE MR0175/ISO 15156 . Incoloy A-286 fasteners offer precipitation-hardenable strength up to 1300°F (700°C) with excellent fabricability .
Alloy Comparison & Selection Guide
| Grade | UNS | Strengthening Mechanism | Max Temp (°F) | Key Feature | Primary Application |
|---|---|---|---|---|---|
| Incoloy 800 | N08800 | Solid-solution | 1100 | General high-temperature service | Heat exchangers, furnace components |
| Incoloy 800H | N08810 | Solid-solution (controlled grain size) | 1200+ | High creep-rupture strength | Petrochemical, power generation |
| Incoloy 800HT | N08811 | Solid-solution (Al+Ti control) | 1200+ | Maximum high-temperature strength | High-temperature construction |
| Incoloy 825 | N08825 | Solid-solution (Ti-stabilized) | 1000 | Sulfuric acid & SCC resistance | Chemical processing, marine |
| Incoloy 925 | N09925 | Age-hardenable (γ’) | 1000 | Sour gas + high strength | Oil & gas down-hole |
| Incoloy A-286 | S66286 | Age-hardenable (γ’) | 1300 | High strength + non-magnetic | Aerospace, turbochargers |
Fastener Types & Product Range
Standard Product Forms
| Fastener Type | Description | Available Grades |
|---|---|---|
| Hex Bolts | Hexagon head bolts, full or partial thread | 800/825/925/A-286 |
| Hex Nuts | Standard hex nuts, heavy hex nuts | 800/825/925/A-286 |
| Stud Bolts | Fully threaded or double-end studs | 825/925/A-286 |
| Socket Head Cap Screws | High-strength internal hex drive | A-286, 925 |
| Machine Screws | Precision threads for machinery | All grades |
| Threaded Rods | Continuous threading, custom lengths | 825/800 |
| Washers | Flat washers, spring washers | All grades |
| Hex Set Screws | Headless threaded fasteners | A-286, 925 |
| Foundation Bolts | Heavy-duty anchoring bolts | 800, 825 |
| U-Bolts | Bent bolts for pipe support | 825, 800 |
Alloy | ASTM | DIN | BS | AFNOR | GB | |
|---|---|---|---|---|---|---|
New grades | Old grades | |||||
| Incoloy 800 | UNS N08800 | 1.4876 / X10NiCrAlTi3220 | NA15 | Z8NC32.21 | NS1101 | NS111 |
| Incoloy 800H | UNS N08810 | 1.4958 / X5 NiCrAlTi 31-20 | NA 15 (H) | NS1102 | NS112 | |
| Incoloy 800HT | UNS N08811 | 1.4959 / X 8 NiCrAlTi 32-21 | ||||
| Incoloy 825 | UNS N08825 | 2.4858 / NiCr21Mo | NA16 | NC21FeDu | NS1402 | NS142 |
| Incoloy 925 | UNS N09925 | 1.4529 / X1NiCrMoCu | ||||
| Incoloy 926 | UNS N08926 | 1.4529 / X1NiCrMoCu | X1NiCrMoCu | X1NiCrMoCu | ||
| Incoloy 901 | UNS N09901 | 2.4662 | ||||
| Incoloy 330 | UNS N08830 | |||||
