COMPREHENSIVE TECHNICAL ANALYSIS AND DATASHEET OF INCOLOY 800 (UNS N08800) FASTENING SYSTEMS
Incoloy 800 (officially designated as UNS N08800) is a nickel-iron-chromium alloy engineered for structural applications requiring high strength and resistance to oxidation and carburization at elevated temperatures. With a balanced chemical composition, Alloy 800 remains stable during long-term exposure to high heat, preventing the embrittlement that often plagues standard stainless steels.
This alloy is the foundational grade of the 800-series, designed to operate in environments up to 1100°F (593°C). It offers excellent resistance to many aqueous corrosive environments and is particularly valued in the power generation and petrochemical sectors for its ability to maintain mechanical integrity and structural stability under thermal stress.
■ Product Overview & Specifications
Incoloy 800 fasteners are typically supplied in the annealed condition to ensure a balanced profile of ductility, toughness, and corrosion resistance for industrial high-temperature service.
| Material Classification | Nickel-Iron-Chromium Alloy |
|---|---|
| UNS Designation | N08800 |
| Microstructure | Austenitic |
| Magnetic State | Non-Magnetic |
| Density | ~7.94 g/cm³ (0.287 lb/in³) |
| Melting Range | 2475°F – 2525°F (1357°C – 1385°C) |
| Size Range | Metric: M6 to M100 | Imperial: 1/4" to 4" Custom U-bolts and heavy hex bolts available. |
| Thread Types | UNC, UNF, 8UN, Metric Coarse, Metric Fine |
■ Proprietary Datasheet Download (GATED)
Access professional-grade technical data for Incoloy 800, including ASME Boiler and Pressure Vessel Code (BPVC) allowable stress values, oxidation rate charts, and specialized weldability data.
Incoloy 800 (N08800) — Complete Technical Datasheet
Contains detailed thermal expansion mapping, ASME Section VIII Design stress tables, and specific installation torque values for high-heat flange assemblies.
⬇ DOWNLOAD DATASHEET■ MTC Integration Section
To guarantee performance in pressurized thermal systems, Ananka Group provides 100% material traceability and certified testing results.
- EN 10204 Type 3.1: Detailed reporting of actual chemical analysis, mechanical test results (Tensile, Yield, Elongation), and hardness verification to ensure compliance with ASTM standards.
- EN 10204 Type 3.2: Third-party witness testing (e.g., TUV, BV, or SGS) is facilitated for critical petrochemical reactors or power plant infrastructure.
■ Chemical Composition (UNS N08800)
The high Nickel content provides resistance to chloride stress-corrosion cracking, while the Chromium offers resistance to oxidation. The Iron content ensures the alloy remains a cost-effective alternative to high-nickel superalloys.
| Nickel (Ni) | Chromium (Cr) | Iron (Fe) | Carbon (C) | Aluminum (Al) | Titanium (Ti) | Manganese (Mn) |
|---|---|---|---|---|---|---|
| 30.0 – 35.0 | 19.0 – 23.0 | 39.5 Min | 0.10 Max | 0.15 – 0.60 | 0.15 – 0.60 | 1.50 Max |
*Silicon (1.0 Max), Sulfur (0.015 Max), and Copper (0.75 Max) are controlled to ensure optimal thermal stability.
■ Mechanical Properties
Incoloy 800 provides moderate strength at room temperature and maintains significant structural integrity at elevated temperatures up to its service limit of 1100°F.
| Property | Annealed Condition (Typical) |
|---|---|
| Tensile Strength (Min) | 75 ksi (520 MPa) |
| Yield Strength (0.2% Offset, Min) | 30 ksi (205 MPa) |
| Elongation in 2" (Min) | 30% |
| Hardness (Typical) | ~70 - 85 HRB |
■ Equivalent Grades & Designations
| Standard / System | Designation |
|---|---|
| UNS Designation | N08800 |
| Common Trade Name | Incoloy 800®, Alloy 800 |
| ASTM Specifications | ASTM A240, B408, B409 |
| European Equivalent | W.Nr. 1.4876 / X10NiCrAlTi32-20 |
■ Applications & Industries
Alloy 800 is the industry standard for high-temperature equipment in the following sectors:
- Power Generation: Superheater and reheater tubing fasteners and structural components in coal-fired and nuclear power plants.
- Petrochemical Processing: Heat exchangers, process piping, and pressure vessel fasteners handling high-heat fluids.
- Heat Treating: Furnace hardware, radiant tubes, and fixtures subjected to continuous thermal cycling.
- Chemical Industry: Nitric acid coolers and components requiring resistance to organic and inorganic chemicals.
■ Compatible Fastener Assemblies
To ensure uniform thermal expansion and prevent galvanic reaction in high-heat systems, Alloy 800 components are typically paired with similar high-nickel alloys.
| External Threads (Incoloy 800) | Recommended Mating Component (Nuts) |
|---|---|
| Incoloy 800 Stud Bolts | Incoloy 800 Heavy Hex Nuts |
| Incoloy 800 Hex Bolts | Incoloy 800 Standard Hex / Jam Nuts |
■ Torque & Installation Guidelines
Like all nickel-based alloys, Incoloy 800 is susceptible to thread galling. The use of high-quality, high-temperature anti-seize lubrication is non-negotiable for accurate installation and future maintenance.
| Nominal Diameter | Threads Per Inch (UNC) | Target Torque — Lubricated (ft-lbs) |
|---|---|---|
| 1/2" | 13 | 40 - 50 |
| 5/8" | 11 | 80 - 100 |
| 3/4" | 10 | 140 - 170 |
| 1" | 8 | 340 - 390 |
■ Why Choose Ananka Group?
Ananka Group specializes in the manufacturing of reliable fastening solutions for global energy and chemical infrastructure.
- In-House Manufacturing: Complete control over production from premium raw material selection to precision thread rolling and final testing.
- 100% Traceability: Every fastener is heat-number traceable, ensuring metallurgical integrity for safety-critical systems.
- Advanced Machining: Expertise in handling tough-to-machine nickel alloys to ensure perfect thread profiles and dimensional accuracy.
- Global Certifications: ISO 9001:2015 certified processes and strict adherence to international ASTM and ASME standards.
■ Frequently Asked Questions
1. What is the difference between Incoloy 800, 800H, and 800HT?
While sharing the same chemistry, 800H has a higher Carbon content (0.05-0.10) and a larger grain size for better creep resistance. 800HT adds further restricted Aluminum and Titanium levels for maximum creep strength. Standard 800 is typically used for temperatures below 1100°F where creep is not the primary design factor.
2. Is Incoloy 800 magnetic?
No. Incoloy 800 is a fully austenitic alloy and remains non-magnetic under all standard operating conditions.
3. Can Incoloy 800 be used in saltwater?
Incoloy 800 offers good resistance to many corrosive environments, but for continuous seawater exposure, Super Austenitic alloys (like AL-6XN) or Super Duplex steels are generally preferred due to their higher resistance to chloride pitting.
4. Does Incoloy 800 require special welding procedures?
Yes. When welding Alloy 800, it is critical to use matching filler metals (like Inconel 82 or 617) to ensure the weld joint maintains the same oxidation resistance and high-temperature strength as the base material.