FIELD: machine engineering, particularly manufacture of parts by sheet forming of refractory metals and alloys in electronic tube production. SUBSTANCE: method comprises steps of selecting temperature of preheating blank at constant temperature of preheating fitting (lower die, punch) of delivery lot; visually determining preheating degree according to iridescence colors as part of blank surface is not lubricated. EFFECT: enhanced quality, increased yield of valid parts at drawing and sizing operations due to elimination of metal flaws. 2 cl, 2 ex
