A Ni-Cr alloy with very good high temperature stability
Good high temperature strength- Oxidization and carburization resistant at high temperatures
- Good corrosion resistance, which increases with the various grades
- Incoloy vented screw features & benefits
- Download the Incoloy 800 datasheet and 825 datasheet
Not to be confused with Inconel, Incoloy vented screws 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 nickel alloy screws 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:
Datasheets: Incoloy 800, 800H 800HT; Incoloy 825; and Incoloy 925
Resources: Incoloy Torque Specs, Flange Dimensions, Flange Bolting Chart
Incoloy Fastener Types: Bolts, Nuts, Screws, Threaded Rods, Washers
Screw Types Available: 12 Point Screws, Button Head Cap Screws, Flat Head Screws, Hex Head Cap Screws, Pan Head Screws, Set Screws, Socket Head Cap Screws, Tamper Resistant Security Screws, Torx Screws, Vented Screws
Incoloy Vented Screw Features & Benefits
Incoloy vented screws are ideal for use in high vacuum (UV) and ultra high vacuum (UHV) equipment, as well as other high pressure environments and applications where gas pockets can form. Center vented screws have a center bore drilled through their axis from the head through the threaded shank of the screw. This feature provides an outlet for the complete evacuation of trapped air and gas contaminants to be pumped away from blind-tapped screw holes, bottoms, sides and shoulders. In addition to vented screws, washers with vent grooves can be made to ensure the venting of the cavity found under the screw head.
Incoloy Vented Screws Benefits
• Enables faster, more efficient pump-down of HV & UHV systems
• Eliminates virtual leaks
• Relieves pressure from blocked gases
• Provides means to vent contaminants found in screw voids
• Promotes higher system throughput and improved yield
• Allows for constant pressure and temperature equalization
Incoloy Vented Screws Are Available In:
Grades: Incoloy 800HT, Incoloy 825, and Incoloy 925
Styles: Socket Head Cap Screw and Hex Head Cap Screw
What is a vented washer?
When a screw is tightened over a flat washer, or directly an application without a washer, volumes of gas can be trapped in the space and beneath the fastener head along the screw shaft. Vented washers feature two bored canals on opposite sides of the flat face which provide an escape route for trapped gases.
What is a virtual leak?
A virtual leak is comprised of gases that are trapped physically within a pocket with only a miniscule escape path from the trapped pocket of gas into the chamber proper.
Common Incoloy Chemistry, Grades & Specifications
Incoloy 800, 800H, H00HT
Incoloy 800 series screws are best utilized for applications that require stable structure and good strength during prolonged exposure to high temperatures.
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
Related to the Incoloy 800 series alloys, Incoloy 825 differentiates itself with the additional elements of molybdenum and copper, which provides it improved corrosion resistance.
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.
Incoloy 925 Specifications: UNS N09925, ASTM B637, NACE MR0175 
Mechanical Properties of Incoloy
