Patent ID: 7670091

Claim:
A bolt for screwing into a nut in a screwing-in revolution direction, said bolt including a shank portion extending along an axis and having a free end, said shank portion bearing a thread having a bottom, said thread having an entrance which is adjacent said free end and being made discontinuous by notching crosswisely said thread as deep as the bottom to form a plural number of substantially triangular notched faces, each of said substantially triangular notched faces being a leading edge surface of a portion of the discontinuous thread and having a base extending at a constant radial distance from said axis, said substantially triangular notched faces comprising a substantially triangular entrance notched face at the entrance of the thread and at least one substantially triangular inner notched face, said substantially triangular entrance notched face having a base that, as viewed in projection in a plane containing said axis, extends toward said free end at an angle α to said axis ranging between +15° and +80°, and each said substantially triangular inner notched face having a base that, as viewed in projection in a plane containing said axis, extends toward said free end at an angle θ to said axis ranging between −15° and −80°, wherein + and − respectively designate directions toward and away from the screwing-in revolution direction with respect to said axis; and wherein, when said bolt is screwed into a nut, said entrance notched face corrects oblique screwing.