This combination is consistent with the essence of modernization, which want to offer such a famous fixture as a screw. It is clear to everyone that it holds better than a nail, but it requires more effort and time for screwing. If it is to drive with a hammer, the material is crushed, it does not form a threaded groove. My screw (1) with longitudinal grooves on the threaded part, produced by forcing through a die (2). It is possible to drive a nail. You only need a little then turn the bolt with a screwdriver: the remaining part of the coils will cut into the material and will hold securely.
C. CUTTINGS, Leningrad
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