Legend:
b – length of the thread (at least)
l – length of bolt
d – the nominal diameter of the thread
k – head height
r – radius
e – the diameter of the circumscribed circle (not less than)
s – size hex head turnkey
c – thickness of the mounting collar
ds – diameter of the screw shank
u – thread run
lg – length of the shank to thread
ls – length of the shank to the start of the thread
da – the maximum diameter of the stem at the head of the screw
dw – minimum diameter of the seat
k´ – minimum size of the head on the key
Post time: Mar-01-2022