Incoloy Fasteners

A Ni-Cr alloy with very good high temperature stability

• Oxidization and carburization resistant up to 1400°F / 760°C
• Good corrosion resistance, which increases with the various grades
• Download the Incoloy 800 datasheet and 825 datasheet

Not to be confused with Inconel, Incoloy fasteners are made of a nickel alloy which contains iron and a lower content of nickel. Incoloy is essentially a more economical option to Inconel, yet with more restricted corrosion resistance and temperature limits. Typically, Incoloy is an ideal material for long-term exposure in high temperature environments due to its oxidation, carburization and creep resistance. Incoloy is widely used for its resistance to seawater, brine, sour gas and high chloride environments at elevated temperatures, which make it a popular choice in the oil and gas and power industries. 

The most commonly used grades of Incoloy fasteners are Incoloy 800, 800H, 800HT; Incoloy 825; and Incoloy 925. For more indepth information on these specific grades, visit our specific web pages or contact one of our engineering experts:

• Incoloy 800, 800H, 800HT (1.4876, 1.4958, 1.4959)
• Incoloy 825 (2.4858)
• Incoloy 925

Datasheets: Incoloy 800, 800H 800HT; Incoloy 825; and Incoloy 925

Resources: Incoloy Torque Specs

Incoloy Fastener Types: Bolts, Nuts, Screws, Threaded Rods, Washers

Common Incoloy Chemistry, Grades & Specifications

Incoloy 800, 800H, H800HT (1.4876, 1.4958, 1.4959)

Incoloy 800 series fasteners are best utilized for applications that require stable structure and good strength during prolonged exposure to high temperatures.  Learn more by downloading out Incoloy 800 datasheet.

Incoloy 800, 800H & 800HT Specifications: UNS N08800/ N08810 / N08811 (800, 800H, 800HT), ASTM B408, ASME SB408, ASTM B564/ASME SB564, EN 10204-3.1, Werkstoff 1.4876 (800), Werkstoff 1.4876 H and 1.4958 (800H), Werkstoff 1.4876 HT and 1.4959 (800HT)

Incoloy 825 (2.4858)

Related to the Incoloy 800 series alloys, Incoloy 825 (2.4858) differentiates itself with the additional elements of molybdenum and copper, which provides it improved corrosion resistance. Learn more by downloading out Incoloy 825 datasheet.

Incoloy 825 Specifications: UNS N08825, BS 3076NA16, ASTM B 425, ASTM B 564, ASME SB 425, ASME SB 564, ASME Code Case N-572, DIN 17752, DIN 17753, DIN 17754, VdTÜV 432, ISO 9723, ISO 9724, ISO 9725, Werkstoff Nr 2.4858

Incoloy 925

Incoloy 925 is a precipitation hardened alloy. It offers comparable corrosion resistance to it’s sister alloy Incoloy 825, but with the increased strength resulting from the age hardening process. Learn more by downloading out Incoloy 925 datasheet.

Incoloy 925 Specifications: UNS N09925, ASTM B637, NACE MR0175

Mechanical Properties of Incoloy

Incoloy 800 Series Fasteners & Flanges

A Ni-Cr alloy with very good high temperature stability (1.4958, 1.4876 and 1.4959)

Incoloy 800 fasteners and flanges are best utilized for applications that require stable structure and good strength during prolonged exposure to high temperatures. These fasteners are utilized in a diversity of industries involving corrosive environments and high temperatures. Incoloy 800 series nickel alloys include Incoloy 800, 800H, and 800HT. All are identical except for the higher level of carbon in alloy 800H and the addition of approximately 1.20 percent aluminum and titanium in 800HT. Incoloy 800H offers improved stress rupture properties over 800. Incoloy 800HT further improves on this to ensure optimum high temperature properties.  Learn more by downloading our datasheet.

Corrosion Resistance

• Good strength and excellent resistance to oxidation and carburization in high-temperature exposure
• Good high temperature strength
• High creep rupture strength
• Good corrosion resistance in many acidic environments
• Good resistance to many sulfur-containing atmospheres

Temperature Guidelines

Incoloy 800 is primarily used in applications with temperatures up to 1100° F, where alloys 800H and 800HT are normally used in temperatures above 1500°F where creep and stress rupture protection are a critical concern.  Incoloy 800HT will not become embrittled even after long periods of usage in the 1200-1600° F. When exposing Incoloy 800 to aggressive media in the temperature range of 1000 to 1400°F, it can be sensitized and made susceptible to intergranular attack.

Applications

• Industrial and chemical processing industries look to Incoloy 800 series fasteners for the construction of heat exchangers and process piping, as well as carbonizing equipment and heating element sheathing.
• Nuclear power plants require Incoloy 800 for steam generators, while the pulp and paper industry needs these fasteners digestor-liquor heaters.
• Chemical and petroleum processing employ Incoloy 800 fasteners for heat exchangers and other environments containing nitric acid media, as well as for applications where resistance to chloride stress-corrosion cracking is required.

Incoloy 800 Physical Properties

• Density: 0.27 lbs/in³, 7.94.g/cm³
• Specific Heat, Btu/lb•°F, J/kg•°C:
• 32-212°F (0-100°C): 0.11 (460)
• Mean Coefficient of Thermal Expansion: in/in/°F (mm/m/°C) 70- 212°F (20- 100°C)– 7.9 x 10-6 (14.2)
• Thermal Conductivity: BTU/h-ft-°F (W/m-°K): 70°F (21°C): 6.7 (11.6)
• Modulus of Elasticity: ksi (MPa) 28.5 x 10³ (196.5 x 10³) in tension
• Permeability at 70°F (21°C) H= 200 Oersted : Annealed : 1.014
• Melting Point: 2525°F (1385°C)

Incoloy 800 Strength Properties

• Ultimate Tensile Strength: 75 KSI min (420 MPa min)
• Yield Strength (0.2% offset): 30 KSI (gauges ≥ 0.020 inches)
• Elongation: 30% min
• Hardness: Rb 84 nom

*Annealed Typical at room temperature

Resources: Incoloy Torque Specs, Flange Dimensions, Flange Bolting Chart

Incoloy Fastener Types: Bolts, Nuts, Screws, Threaded Rods, Washers

Flange Types Available: Blind Flanges, Lap Joint Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Weld Neck Flanges 

Incoloy 800, 800H & 800HT Chemistry and Specifications

Incoloy 800, 800H & 800HT Specifications: UNS N08800/ N08810 / N08811 (800, 800H, 800HT), ASTM B408, ASME SB408, ASTM B564/ASME SB564, EN 10204-3.1, Werkstoff 1.4876 (800), Werkstoff 1.4876 H and 1.4958 (800H), Werkstoff 1.4876 HT and 1.4959 (800HT)

Incoloy 800 Mechanical Properties

Incoloy 825 Fasteners & Flanges

Improved corrosion resistance to Incoloy 800, same high temp stability (2.4858)

Related to the Incoloy 800 series alloys, this specialty nickel alloy differentiates itself with the additional elements of molybdenum and copper, which provides it improved corrosion resistance – specifically pitting and crevice corrosion, as well as reducing environments. In addition to its strength and corrosive properties, it also offers good weldability by all conventional processes. Learn more by downloading our Incoloy 825 (2.4858) datasheet.

Corrosion Resistance

Primary corrosive environments where Incoloy fasteners and flanges are most useful are sulfuric acid, phosphoric acid, sulfur-containing flue gases, sour gas and oil wells, and sea water.

• Improved resistance to aqueous corrosion compared to Incoloy 800
• Excellent resistance to both reducing and oxidizing acids
• Especially resistant to sulfuric and phosphoric acids
• Good resistance to chloride stress-corrosion cracking, as well as pitting and crevice corrosion
• Good resistance to a variety of oxidizing substances such as nitric acid, nitrates and oxidizing salt
• Good resistance to stress-corrosion cracking in neutral chloride media.

Gain a better understanding of Incoloy 825's corrosion performance in:

• Sulfuric Acid
• Hydrochloric Acid

Temperature Guidelines

Alloy 825 fasteners and flanges have good mechanical properties from cryogenic temperatures to moderately high temperatures up to approximately 1000° F. When used at temperatures above 1000° F microstructural changes will occur that significantly lower ductility and impact strength.

Applications

• Chemical processing utilizes Incoloy 825 fasteners for their resistance to sulfuric and phosphoric acid which makes it useful in acid production and pickling.
• Nuclear relies on these fasteners for fuel reprocessing, fuel element recovery and radioactive waste handling.
• Resistant to both localized and general corrosion, Incoloy also plays a role in a broad range of additional industries including pollution control and oil & gas. 

Incoloy 825 Physical Properties

• Density: 0.294 lbs/in³, 8.14 g/cm³
• Specific Heat, (32-212°F),Btu/lb•°F, (0-100°C), J/kg•°C: 0.105 (440)
• Mean Coefficient of Thermal Expansion: in/in/°F (mm/m/°C): 70- 212°F (20- 100°C): 7.7 x 10-6 (13.9)
• Thermal Conductivity BTU/h-ft-°F (W/m-°K):  70°F (21°C): 6.4 (11.1)
• Modulus of Elasticity, ksi (MPa): 28.4 x 10³ (196 x 10³) in tension
• Melting Range: 2500-2550°F (1370-1400°C)

Incoloy 825 Strength Properties

• Ultimate Tensile Strength: 100 KSI min (690MPa min)*
• Yield Strength: (0.2% offset) 47KSI min (324MPa min)*
• Elongation: 45%*

*Annealed, Typical at room temperature

Resources: Incoloy Torque Specs, Flange Dimensions, Flange Bolting Chart

Incoloy Fastener Types: Bolts, Nuts, Screws, Threaded Rods, Washers

Flange Types Available: Blind Flanges, Lap Joint Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Weld Neck Flanges

Incoloy 825 Chemistry and Specifications

Incoloy 825 Specifications: UNS N08825, , BS 3076NA16, ASTM B 425, ASTM B 564, ASME SB 425, ASME SB 564, ASME Code Case N-572, DIN 17752, DIN 17753, DIN 17754, VdTÜV 432, ISO 9723, ISO 9724, ISO 9725, Werkstoff Nr 2.4858 

 Incoloy 825 Mechanical Properties

Incoloy 825 Sulfuric Acid Iso-Corrosion Curve

Incoloy 825 Hydrochloric Acid Iso-Corrosion Curve

Incoloy 925 Fasteners & Flanges

An age hardened version of Incoloy 825 with improved strength.

Incoloy 925 fasteners and flanges are made of a precipitation hardened nickel alloy. It offers comparable corrosion resistance to it’s sister alloy Incoloy 825, but with the increased strength resulting from the age hardening process. In addition, Incoloy 925 also contains additional levels of titanium and aluminum compared to 825. Incoloy 925 fasteners and flanges are ideal for use in applications that require a combination of high strength and corrosion resistance. For more indepth information, download our Incoloy 925 datasheet.

Corrosion Resistance

Incoloy 925 fasteners and flanges are known to have outstanding resistance to general corrosion, pitting, crevice corrosion, and stress-corrosion cracking in many aqueous environments including those containing sulfides and chlorides. In addition, the higher nickel content than Incoloy 800, gives it improved protection against chloride-ion stress corrosion cracking. The added molybdenum and copper provides resistance to reducing chemicals.

• Good protection in oxidizing and reducing atmosphere
• Good resistance to chloride ion stress-corrosion cracking
• Excellent resistance to pitting and crevice corrosion

Temperature Guidelines

Incoloy 925 fasteners and flanges remain strong at temperatures up to 1200°F (650°C).

Applications

• Often used for down-hole and surface gas-well because of their excellent resistance to sulfide stress cracking and stress-corrosion cracking in “sour” (H2S containing) crude oil and natural gas.

• Marine and pump shafts or high-strength piping systems.

Incoloy 925 Physical Properties

• Density (lb / cu. in.): 0.292
• Specific Gravity: 8.14
• Specific Heat (Btu/lb/Deg F - [32-212 Deg F]): 0.109
• Electrical Resistivity (microhm-cm (at 68 Deg F)): 701
• Melting Range (Deg F): 2392-2490
• Poissons Ratio: 0.281
• Mean Coefficient of Thermal Expansion: 7.32
• Magnetic Permeability: 1.01
• Modulus of Elasticity Tension: 28.7

Incoloy 925 Strength Properties

For common comparison, Incoloy 925 (167.3 ksi tensile, solution treated & aged) offers a level of strength that is greater than Inconel 625 (144 ksi tensile) but less than that of age-hardened Inconel 718 (210 ksi tensile, annealed & aged).

Resources: Incoloy Torque Specs, Flange Dimensions, Flange Bolting Chart

Incoloy Fastener Types: Bolts, Nuts, Screws, Threaded Rods, Washers

Flange Types Available: Blind Flanges, Lap Joint Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Weld Neck Flanges

Incoloy 925 Chemistry and Specifications

Incoloy 925 Specifications: UNS N09925, ASTM B637, NACE MR0175  

 Incoloy 925 Mechanical Properties