METHOD OF PRODUCING ARTICLE OF DOOR FASTENER TYPE Russian patent published in 2012 - IPC B21K1/44 

FIELD: process engineering.

SUBSTANCE: invention relates to metal cold forming and may be used in upsetting fasteners by cold forming. Proposed method comprises billet cutting, forming of article and upsetting of cylindrical flange. Forming aforesaid article is carried in four passes. At first pass, cylindrical section with diameter d₁ is reduced on head face side together with upsetting the taper section. At second pass, guide section made up of two radii r₁ and r₂ is reduced to shape head face to diameter d₂. Diameter d₂ is not changed in next passes. Simultaneously, cylindrical section is upset in second pass to diameter d₃. In third pass hexagon is pre-formed by upsetting. Said hexagon is finally formed in fourth pass together with taper section made at angle α and cylindrical flange is upset.

EFFECT: higher quality of article.

1 dwg