A Fe-Ni-Cr alloy with excellent high temperature oxidation resistance

Vented screws made from A-286 are known for their high strength, creep resistance and oxidation resistance at elevated temperatures. This iron-nickel-chromium alloy (once age-hardened) provides A-286 vented screws with high levels of strength from room temperature up to about 1300°F (700°C).

A-286 vented screws are mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1300°F (700°C) in conditions that would typically be found in high temperature exhaust streams.

Because of these properties, A286 vented screws are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications.

Resources: A-286 Torque Specs

Screw Types12 Point ScrewsButton Head Cap ScrewsFlat Head ScrewsHex Cap ScrewsPan Head ScrewsSet ScrewsSocket Head Cap ScrewsTorx Screws


A286 Vented Screw Features & Benefits

A286 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.

A286 Vented Screws Benefits
• Enables faster, more efficient pump-down of HV & UHV systems
• Eliminates virtual leaksVented Screw TextCrop
• 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

A286 Vented Screws Are Available In:
•  Socket Head Cap Screw
•  Hex Head Cap Screw

vented washer

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.

 


A-286 Chemistry, Specifications & Heat Treatments

A-286 Heat Treatments:  There are several heat treatment combinations for A-286 all with slight variations in performance. They can be specified via an AMS number or a 660 Class: A, B, C or D,  with most common specified as class A or D.   The A-286 grades A, B and C all have the same min tensile strength and min yield strength of 130ksi and 85ksi respectively. However grade D is significantly better yield with a min tensile of 130ksi and a min yield of 105ksi. 

By AMS numbers, the most common for A-286 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B). 

A-286 Specifications: AMS 5525, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, UNS S66286, Werkstoff 1.4980

A 286 Chemistry


Mechanical Properties

A-286 Tensile Curves

 

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