Oxidation Resistant A286 and Alloy 330 Bolt

Q: I was reading that high temperatures will accelerate the rusting of metal bolts. Is there a material that can prevent this. I’m using the screws at 1300F intermittently.

A: What you are looking for is an oxidation resistant bolt. When a metal oxidizes it is attacked by oxygen which accelerates at high temperatures. Depending on the strength requirements of your application but Alloy 330 bolts and A286 bolts are ideal for preventing oxidation, hence rust at high temperatures. They also work well for 1300F of intermittent heat.

Oxidation Resistance for Heat Treating

Q: I am interested in 1/4″ x 2 1/2′ bolts and nuts that can resist oxidation up to 2000F. The application they are needed for would be to hold together a steel frame meant to hold tool steel in position preventing distortion during the heat treating process. I would like a recommendation for the best alloy to use in this application.

A: Probably the best alloy to consider in an application like this are Alloy 330 fasteners. This alloy is designed for its high temperature oxidation resistance and stability. Alloy 330 bolts are often used in heat treating applications and would be worth considering.

Inconel 600 Bolts & Alloy 330 Bolts for High Temperature Oxidation

Q: I have an application that requires high temperature oxidation resistance up to about 2000F. Any suggestions?

A: For these conditions there are two options I would suggest. You could try Inconel 600 bolts which are usable to 2000F. They offer excellent carburization and oxidation resistance. Since your process is at the limit of Inconel 600 you may also want to consider Alloy 330 bolts. Alloy 330 also offers excellent oxidation resistance. In addition, it performs very well in cyclic temperature conditions.

How to Choose High Temp Oxidation Resistant Fasteners

From thermal processing and furnace applications to the extreme demands of aerospace, several high temperature alloys are available each with unique traits and capabilities. This brief newsletter will outline the primary fastener materials that are commonly used for excellent high temperature and oxidation resistance.

Best High Temperature Oxidation Resistant Fasteners

ALLOY 330
Developed for furnace applications, Alloy 330 fasteners are ideal for high temperature oxidation and caburization resistance. They are one of few materials that can handle extreme temperature changes, plus alternate carburizing and oxidizing atmospheres. KEY TRAIT: Performance under cyclic heating & cooling

INCONEL 625
Inconel 625 bolts deliver a unique package of corrosion, oxidation and carburization resistance combined with high temperature strength. Their nickel and chromium content provides resistance to a many of harsh chemicals including sulfuric acid. KEY TRAIT: Great high temp stability & strength, in even in corrosive environments

WASPALOY
Fasteners made from this unique alloy offer extreme temperature and oxidation resistance in combination with high strength. Waspaloy is one of the strongest fasteners available for use over 1300°F. KEY TRAIT: Extreme strength at high temperatures

A286 / ALLOY 660
Age hardened, Alloy 660 / A286 fasteners offer good oxidation and creep resistance, as well as high temperature strength. They are most commonly used in high temperature exhaust streams. KEY TRAIT: Very good strength at high temperatures

310SS
Offering good strength under mildly cyclic conditions. Alloy 310 fasteners also offer good resistance to oxidation, carburization, and other forms of hot corrosion. KEY TRAIT: Economic high temperature alloy for moderate strength applications

Don’t Forget About Ceramics

Ceramics offer extreme high temperature capabilities and are virtually inert to corrosive substances. Alumina fasteners can be used up to temperatures of 3000°F, while Zirconia fasteners can be used to 4000°F. While ceramics are extremely temperature and corrosion resistant they are brittle and cannot be used in high strength applications.