Rolled Alloy’s RA353MA Alloy was selected as the material of construction for a copper brazing furnace muffle. The muffle, which operates at 2150 degrees F in a hydrogen atmosphere, had previously been made of Alloy 601 material, and normally provided a service life of approximately 8 months. In contrast, the RA 353 MA muffle has now been in service for over 2 years and is still in fine shape. A total of twelve RA 353 MA muffles are currently in this type of high temperature service, with no failures yet reported. RA353MA is a new 25% Cr, 35% Ni, 1.2% Si,.05% Ce alloy with high strength and excellent oxidation resistance in operating conditions of 2000 degrees F and higher. The alloy offers good hot erosion resistance through its high chromium content and rare earth addition, thus making it a strong candidate material for other high temperature applications such as calciners, vortex finders, boiler tube shields and incineration furnaces.