Inconel 600 or 601 Bolts For High Temperatures?

Q: For a high temperature oxidation-rich environment which would be better Inconel 600 or 601 bolts?

A: For this situation it really depends on the temperature range you are dealing with because both an Inconel 600 bolt and an Inconel 601 bolt offer good oxidation resistance. Inconel 600 can service up to 2000F where Inconel 601 can handle up to 2200F. If you temperatures aren’t that severe, I’d suggest A286 bolts for excellent oxidation resistance. An A286 bolt is known for its high strength, creep resistance and oxidation resistance up to 1300F.

A286 Bolts for Improvement Over Grade 8 in Fuel Application

Q: I’m working with a high temperature waste to fuel application that operates at 1000F normally but could spike to 1200F. Currently I am using Grade 8 bolts but I am concerned about the oxidation resistance of them and their stability at high temperatures. Do you have any material recommendations?

A: One of the best materials to consider for your high temperature application is A-286. A286 bolts will be strong, oxidation resistant and thermally stable. This will provide you will an significantly improved solution over Grade 8 alloy steel. An A286 bolt is also usable to 1300F.

A286 Protection From High Temperatures or Corrosive Conditions?

Q: I have an high temperature exhaust application that requires about 130ksi of tensile strength and is running pretty hot at 1000F. There are also some low concentration acidic contaminants that condense on the bolts during shutdowns, that have caused corrosion in the past on standard 316 bolting. Would A286 work with this? It says it is mildly corrosion resistant.

A: An A286 screw is mainly used for high temperature / high strength applications that require oxidation resistance. ex would perform from a corrosion point of view in a very similar way to the 316 stainless steel bolts however it may be VERY difficult for you to differentiate if your “corrosion” problem is due to oxidation of the bolts or your mild acid or both. A286 bolts may solve your oxidation problem, which may be the initial cause of your “corrosion” problems as 316 is not very oxidation resistant. It may be a good test to do, if you can swap out some bolts

Nitronic 60 vs A286 for High Temperatures

Q:How does Nitronic 60 compare to an A286 bolt for high temperature strength?

A: That depends on the strength required and the temperature of your application. A Nitronic 60 bolt is known for its high temperature properties up to 1800F. At these extreme temperatures it can offer good resistance to wear, fretting, and galling; and oxidation resistance comparable to that of 309 stainless. On the other hand it doesn’t offer the high strength of A286. Nitronic 60 offers 95ksi UTS compared to the 120-160ksi UTS of A286. A286 bolts offer excellent high strength, creep resistance and oxidation resistance to a temperature of 1300F – not as high as Nitronic. So it will depend on the temperature range and strength you require.

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.