Window/facade screw fastener

摘要

The fastener has a stainless steel first part positively joined to a second hardened steel part. The first part comprises a head (2) and a shaft (13) as a screw blank (11,10) which in turn is knurled (15) to take the second part as a ring etc. (14). The shaft is threaded (17) beyond the head and knurled part which are spaced by one quarter of the shaft length. The head (20) in the complete screw has an integrated segment (22) adjoined by segment (23) on the second part of the screw. The head end of the segment (22) terminates in a pin (25) which fits positively and with friction into the segment (23) hole (26) assisted by knurling in pin or hole. Segment (22) is threaded (27) and segment (23) is formed into a hardened drill tip (28). The blank is made of non-corroding material, knurled and pressed to a second blank ready for the joining operation between the segments via the knurling prior to threading and tip-forming.