JIS B 1180 Standard

Types of hexagon head bolts

Type Range of nominal diameter d of thread Corresponding International Standard (informative)
Designation Pitch of thread Product Grade
Nominal diameter
hexagon head bolt
Coarse thread A d = 1.6 mm to 24 mm [nominal length l is up to and including 10d or 150 mma)] ISO 4014
B d = 1.6 mm to 24 mm [nominal length l is over
10d or 150 mm a)]
d = 27 mm to 64 mm
C d = 5 mm to 64 mm ISO 4016
Fine pitch thread A d = 8 mm to 24 mm [nominal length l is up to
and including 10d or 150 mm a)]
ISO 8765
B d = 8 mm to 24 mm [nominal length l is over
10d or 150 mm a)]
d = 27 mm to 64 mm
Hexagon head screw bolt Coarse thread A d = 1.6 mm to 24 mm [nominal length l is up to
and including 10d or 150 mm a)]
ISO 4017
B d = 1.6 mm to 24 mm [nominal length l is over
10d or 150 mm a)]
d = 27 mm to 64 mm
C d = 5 mm to 64 mm ISO 4018
Fine pitch thread A d = 8 mm to 24 mm [nominal length l is up to
and including 10d or 150 mm a)]
ISO 8676
B d = 8 mm to 24 mm [nominal length l is over
10d or 150 mm a)]
d = 27 mm to 64 mm
Pitch diameter
hexagon head bolt
Coarse thread B d = 3 mm to 20 mm ISO 4015
Note a) Whichever is the shorter.