Q: I am looking for a suitable fastener for use in a high heat furnace that is running at 2000F but the actual hearth wear flames go up to 3000F. The furnace is not under vacuum and has a normal atmosphere. We are finding that the 304 bolts are failing rapidly and we tried Inconel bolts which are doing better but still failing in about 2-3 weeks. Do you have any recommendations?
A:
At those temperatures in an oxygen rich environment you need to consider ceramic fasteners. As long as your loads are not too high and thermal shock is not an issue, I think this would be your best option.Since your hearth can get up to 3000F, I would recommend using Alumina ceramic bolts which provide thermal resistance to 3000F . In addition, Alumina is almost inert to corrosion including acids, solvents, salts and organics.
At those temperatures in an oxygen rich environment you need to consider ceramic fasteners. As long as your loads are not too high and thermal shock is not an issue, I think this would be your best option.
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