FIELD: tests of parts made of refractory metals and used in electric-vacuum production. SUBSTANCE: procedure determining press-working capacity of cup-shaped parts of electric-vacuum production out of sheets of refractory metals consists in manufacture of laminated specimens and in their test for bending with determination of limit ductility to moment of appearance of first crack established visually with use of magnifying aid with magnification of 2-4. Angles of bending of specimens in process of test are measured and output of good stamped items without any surface rupture is estimated. Bending test is executed with the help of laminated punch that has two roundings of working face in mutually perpendicular planes. First rounding extends over entire width of punch which radius is less or equal to thickness of tested laminated specimen, second rounding runs from edge to edge over entire width of laminated punch which radius is greater than width of tested specimen. EFFECT: provision for testing with initiation and development of crack in center of specimen, potential for early detection of first crack of smallest possible dimension. 5 dwg, 3 tbl
