Hole forming and selftapping screw of up to approximately 6 mm thread diameter for tapping into sheet metal of a thickness of up to approximately 1 mm comprising a head including a formation for receiving a tool, a thread shank and a cylinder member following thereon having a diameter less than the thread-pitch diameter of the thread shank, merging into a tapered hole forming member. The thread shank merges with the cylinder member via a taper extending over approximately four threads, a distance corresponding approximately to the four-fold sheet metal thickness. The hole forming member terminates in a convexly curved friction surface corresponding to a radius (R) of approximately 0.5 mm. The entire screw is formed in one piece of tempered steel having a tensile strength of up to approximately 1400 N/mm2, mechanically hardened steel respectively.
申请公布号
DE59001719(D1)
申请公布日期
1993.07.15
申请号
DE1990501719
申请日期
1990.03.23
申请人
EJOT EBERHARD JAEGER GMBH & CO KG, 5928 BAD LAASPHE, DE
发明人
GROSSBERNDT, HERMANN, W-5928 BAD LAASPHE, DE;KRETSCHMER, GUENTER, W-5900 SIEGEN, DE;KLEES, HORST, W-3565 BREIDENBACH-ACHENBACH, DE;GUEVEN, ALI, W-5920 BAD BERLEBURG, DE