The materials supplied in accordance with this specification are to be produced in the arc furnace with AOD refining and subsequent degassing. For material NiCr20TiAl (Nimonic 80A) subsequent re-melting process type VAR or ESR is mandatory, for other material is permitted. They will be subjected to hot-rolling to obtain the bars. They will be also submitted potential to subsequent procedures of extrusion of forging depending on the product to be obtained.