ASTM B408 Incoloy 800H/800HT fasteners
ASTM B408 Incoloy 800H/800HT fasteners
ASTM B408 Incoloy 800H/800HT fasteners are high-performance nickel-iron-chromium alloy fasteners designed for extreme high-temperature environments. They offer excellent creep strength, oxidation resistance, and carburization resistance, making them ideal for aerospace, petrochemical, and furnace components. This product series is available in various types (bolts, nuts, screws) and is typically offered with coatings for enhanced protection.
What are the differences between INCOLOY 800 and 800H?
Generally, Alloy 800 exhibits higher mechanical properties at room temperature and under short-term high-temperature exposure, while Alloys 800H and 800HT offer superior creep strength and rupture strength under prolonged high-temperature exposure.
Gnee Steel is a renowned manufacturer and distributor of Incoloy 800 fasteners in the industry. Gnee Steel manufactures Incoloy 800 fasteners to ASTM A408 standards using the best raw materials, suitable for various industries. Gnee Steel's Incoloy UNS N08800 fasteners meet international and national quality standards. Gnee Steel produces Incoloy 800 fasteners in a well-equipped factory with advanced equipment and technology, enabling us to manufacture ASTM A408 Incoloy 800 fasteners in various shapes and sizes. Gnee Steel welcomes custom orders and manufactures Incoloy UNS N08800 fasteners according to customer requirements. Gnee Steel is a well-known brand in the manufacturing and distribution of Incoloy 800 fasteners. Gnee Steel is committed to providing the best-performing ASTM A408 Incoloy 800 fasteners. Gnee Steel uses high-quality raw materials from its inventory to produce Incoloy UNS N08800 fasteners with excellent oxidation resistance.
ASTM B408 Standard:
This standard covers the specifications for nickel-iron-chromium alloy bars, forgings, and forging stock.
It is typically used in conjunction with ASME SB408 (specification version) and ASTM B564 (for pipe fittings).
Alloy 800H/800HT Bolt/Nut Specifications:
| Specifications | : | ASTM B 408 ASME SB 408 |
| Standard | : | DIN, ASTM, BS and all International Standards |
| Length | : | 3 mm to 200 mm |
| Size | : | M3 – M56 | 3/6″ to 2″ | Custom Sizes |
| Type | : | Hex Head Bolts, Square Bolts, U bolts, Eye bolts, T bolt, Hex Bolt, Lag Bolts, Countersunk Bolts, Hex Head nuts, Square nuts, Lock nuts, Eye nuts, wing nuts, T nuts, Panel Nuts, Coupling Nuts, Dome nuts, Acorn Nuts |
Incoloy 800 fasteners are nickel-chromium-iron alloy fasteners that exhibit resistance to carburization and oxidation in high-temperature environments. These fasteners maintain their austenitic structure and remain stable even after prolonged exposure to high temperatures. They offer good corrosion resistance in aqueous, oxidizing, and reducing environments. These fasteners are primarily suitable for temperatures up to 1100 degrees Celsius.
Incoloy 800 bolts exhibit oxidation and carburization resistance at high temperatures. The balanced chemical composition of Incoloy 800H square nuts results in excellent corrosion resistance in carburizing, oxidizing, and nitriding atmospheres. Aluminum and titanium are listed as intentionally added elements for the first time, and annealed Incoloy 800HT U-bolts differ from solution-treated materials. Incoloy 800 lock nuts do not embrittle even after prolonged use in the temperature range of 1200°F to 1600°F, whereas many stainless steels become brittle in this temperature range. The restricted chemical composition combined with high-temperature annealing treatment ensures that these materials have higher creep strength and fracture strength than Incoloy 800H bolts.
ASTM A408 Incoloy 800 fasteners are applicable in various industries. Incoloy 800 fasteners are widely used in several fields, including chemical and petrochemical processing. Heat treatment equipment and heat exchangers are also manufactured using Incoloy UNS N08800 fasteners. Other uses of Incoloy 800 fasteners include superheaters and reheaters in power plants and industrial furnaces. They are also used in the manufacture of carburizing equipment. Ammonia discharge coolers and process piping systems also utilize Incoloy fasteners. Other applications of Incoloy 800 fasteners include steam methane reforming.
800H/800HT Incoloy Alloy Bolt/Nut Chemical Composition:
| Grade | C | Mn | Si | Fe | S | Cr | Al-Ti | Ni | |
| 800H | min. | 0.05 | – | – | 39.5 | – | 19.0 | 0.15 | 30.0 |
| max. | 0.1 | 1.5 | 1.0 | – | 0.015 | 23.0 | 0.60 | 35.0 | |
| 800HT | min. | 0.06 | – | – | 39.5 | – | 19.0 | 0.85/0.25 | 30.0 |
| max. | 0.1 | 1.5 | 1.0 | – | 0.015 | 23.0 | 1.20/0.60 | 35.0 | |
Incoloy Alloy 800H/800HT Bolt/Nut Mechanical Properties:
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 800H-HT | Psi – 75,000 , MPa – 520 | Psi – 30,000 , MPa –205 | 30 | – | – |
Equivalent Grades for 800H / 800HT Incoloy Bolt/Nut:
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN | OR |
| Incoloy 800H | 1.4958 / 1.4876 | N08810 | NCF 800H | NA 15(H) | ЭИ670 | Z8NC33-21 | X5NiCrAlTi31-20 | XH32T |
| Incoloy 800HT | 1.4859 / 1.4876 | N08811 | NCF 800HT | NA 15(HT) | ЭИ670 | – | X8NiCrAlTi32-21 | XH32T |
Prices of 800H / 800HT Incoloy Bolt/Nut:
| Description | Per Unit (INR) | Price in USD | Price in EURO |
|---|---|---|---|
| Incoloy 800ht Stud Bolt To Astm B 564 Gr. Uns No.8811, Nace Mr-0175. Size: M 30x 3.5 Pitch X 343 Mm Long | 7,690 | 104.24 | 87.40 |
| Incoloy 800ht Stud Bolts In Gr. Uns No.8811 Nace Mr-0175., Sz. M 30 X 3.5mm Pitch X 270mm Long | 5,202 | 70.51 | 59.12 |
| Incoloy 800ht Stud Bolts In Gr. Uns No.8811 Nace Mr-0175., Sz. M30 X 3.5 Mm Pitch X 343 Mm Long | 6,440 | 87.29 | 73.19 |
| 66a-nuts/bolts/screws/washer Made Of Alloysteel Including Stainless Steel-incoloy 800h Studbolt 1 1/4 Inch X 235 Mm Long | 3,207 | 43.47 | 36.45 |
| 66a-nuts/bolts/screws/washer Made Of Alloysteel Including Stainless Steel-incoloy 800h Heavy Hex Nut 1-1/4 Inch -8 Un (2 | 1,685 | 22.84 | 19.15 |
| 66a-nuts/bolts/screws/washer Made Of Alloysteel Including Stainless Steel-incoloy 800h Studbolt 1 1/4 Inch X 265 Mm Long | 3,478 | 47.14 | 39.53 |
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅ Over 18 years of export experience, products sold to more than 80 countries
✅ Certified by ISO, SGS, and BV
✅ Global inventory of Inconel, Hastelloy, Incoloy, and Monel alloy tubing, plates, and bars
✅ Custom processing services available – including cutting, polishing, CNC machining, and packaging
✅ Fast delivery within 7-15 days, supported by global logistics partners
📦 Packaging and Shipping
All stainless steel products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Steel also supplies custom incoloy 800H/HT products in various sizes and specifications. Please send us your drawings for a quote!
Some of the documentation we provide for Incoloy 800 fasteners includes raw material certificates, 100% radiographic testing reports, fumigation certificates, material traceability records, and test certificates conforming to NACE MR0103 and NACE MR0175 standards.
Gnee Steel also conducts several quality tests on its products before delivery. The tests we perform on ASTM A408 Incoloy 800 fasteners include mechanical testing (e.g., tensile area testing), chemical analysis (spectroscopic analysis), positive material identification (PMI) testing, flattening tests, intergranular corrosion (IGC) testing, etc.
