Improvements relating to self-tapping screws, bolts, studs, threaded inserts and thelike

摘要

1,034,054. Self-tapping screws. R. PROCTOR. Feb. 8, 1965 [Feb. 6, 1964], No. 5008/64. Heading B3N. A self-tapping screw or the like has a screwthread of right angle triangular cross-section with a lead-in portion 9, and at least one recess 7 to form cutting edges. The screw may have a screwed bore 10, Fig. 1 (not shown), or it may have a stud portion 11, Fig. 3 (not shown).