Standard

JIS B1181
15° to 30°
c
mw Washer-face form shall be
ordered separately

e 90° to 120° da d dw dw

mw mw
s
m m

Hexagon nuts, style 1-coarse

Dimensions for hexagon nuts, style 1-coarse (first selection)

Designation of screw thread (d) M1.6 M2 M2.5 M3 M4 M5 M6 M8 M10 M12
P (pitch) 0.35 0.4 0.45 0.5 0.7 0.8 1 1.25 1.5 1.75
max. 0.2 0.2 0.3 0.4 0.4 0.5 0.5 0.6 0.6 0.6
c
min. 0.1 0.1 0.1 0.15 0.15 0.15 0.15 0.15 0.15 0.15
max. 1.84 2.3 2.9 3.45 4.6 5.75 6.75 8.75 10.8 13
da
min. 1.6 2 2.5 3 4 5 6 8 10 12
dw min. 2.4 3.1 4.1 4.6 5.9 6.9 8.9 11.6 14.6 16.6
e min. 3.41 4.32 5.45 6.01 7.66 8.79 11.05 14.38 17.77 20.03
max. 1.3 1.6 2 2.4 3.2 4.7 5.2 6.8 8.4 10.8
m
min. 1.05 1.35 1.75 2.15 2.9 4.4 4.9 6.44 8.04 10.37
mw min. 0.8 1.1 1.4 1.7 2.3 3.5 3.9 5.2 6.4 8.3
Reference dimension = max. 3.2 4 5 5.5 7 8 10 13 16 18
s
min. 3.02 3.82 4.82 5.32 6.78 7.78 9.78 12.73 15.73 17.73

Dimensions for hexagon nuts, style 1-coarse (first selection)

(continue)
Designation of screw thread (d) M16 M20 M24 M30 M36 M42 M48 M56 M64
P (pitch) 2 2.5 3 3.5 4 4.5 5 5.5 6
max. 0.8 0.8 0.8 0.8 0.8 1 1 1 1
c
min. 0.2 0.2 0.2 0.2 0.2 0.3 0.3 0.3 0.3
max. 17.3 21.6 25.9 32.4 38.9 45.4 51.8 60.5 69.1
da
min. 16 20 24 30 36 42 48 56 64
dw min. 22.5 27.7 33.3 42.8 51.1 60 69.5 78.7 88.2
e min. 26.75 32.95 39.55 50.85 60.79 71.3 82.6 93.56 104.86
max. 14.8 18 21.5 25.6 31 34 38 45 51
m
min. 14.1 16.9 20.2 24.3 29.4 32.4 36.4 43.4 49.1
mw min. 11.3 13.5 16.2 19.4 23.5 25.9 29.1 34.7 39.3
Reference dimension = max. 24 30 36 46 55 65 75 85 95
s
min. 23.67 29.16 35 45 53.8 63.1 73.1 82.8 92.8
Standard
Dimensions of hexagon nuts, style 1-coarse (second selection)
Designation of screw thread (d) M3.5 M14 M18 M22 M27 M33 M39 M45 M52 M60
P (pitch) 0.6 2 2.5 2.5 3 3.5 4 4.5 5 5.5
max. 0.4 0.6 0.8 0.8 0.8 0.8 1 1 1 1
c
min. 0.15 0.15 0.2 0.2 0.2 0.2 0.3 0.3 0.3 0.3
max. 4 15.1 19.5 23.7 29.1 35.6 42.1 48.6 56.2 64.8
da
min. 3.5 14 18 22 27 33 39 45 52 60
dw min. 5 19.6 24.9 31.4 38 46.6 55.9 64.7 74.2 83.4
e min. 6.58 23.36 29.56 37.29 45.2 55.37 66.44 76.95 88.25 99.21
max. 2.8 12.8 15.8 19.4 23.8 28.7 33.4 36 42 48
m
min. 2.55 12.1 15.1 18.1 22.5 27.4 31.8 34.4 40.4 46.4
mw min. 2 9.7 12.1 14.5 18 21.9 25.4 27.5 32.3 37.1
Reference dimension = max. 6 21 27 34 41 50 60 70 80 90
s
min. 5.82 20.67 26.16 33 40 49 58.8 68.1 78.1 87.8

Types of hexagon head bolts

Corresponding
Range of nominal International
Nuts Pitch Product grade
diameter d (mm) Standard
(informative)

A 1.6 to 16
Coarse ISO 4032:1999
B 18 to 64
Hexagon nut—style 1
A 8 to 16
Fine ISO 8673:1999
B 18 to 64
A 5 to 16
Coarse ISO 4033:1999
B 20 to 36
Hexagon nut—style 2
A 8 to 16
Fine ISO 8674:1999
B 18 to 36
Hexagon nut—C Coarse C 5 to 64 ISO 4034:1999

A 1.6 to 16
Coarse ISO 4035:1999
Hexagon thin B 18 to 64
nut—double
chamfered A 8 to 16
Fine ISO 8675:1999
B 18 to 64
Hexagon thin
Coarse B 1.6 to 10 ISO 4036:1999
nut—unchamfered
Standard
Product specification of hexagon nuts, style 1-coarse
Material Steel Stainless steel Non-ferrous metal

Screw Tolerance zone class 6H

thread JIS B 0205-4, JIS B 0209-1
Applicable standard

d ≤ M24: A2-70, A4-70

d < M3: as agreed between the parties
M24 < d ≤ M39:
concerned with delivery
A2-50, A4-50
Strength division (5) M3 ≤ d ≤ M39: 6, 8, 10
d > M39: as agreed between
d > M39: as agreed between the
the parties concerned with
Mechanical parties concerned with delivery in accordance with
delivery
properties JIS B 1057
M3 ≤ d ≤ M39: JIS B 1052 d ≤ M39: JIS B 1054-2
d < M3 and d > M39: as agreed d > M39: as agreed between
Applicable standard
between the parties concerned with the parties concerned with
delivery delivery
d ≤ M16: A
Product grade
Tolerance d > M16: B
Applicable standard JIS B 1021

As processed Requirements for

electroplating shall be in accordance
with JIS B 1044.

Requirements for non-electrolytically

applied zinc flake coatings shall be in Plain Requirements
accordance with JIS B 1046. for electroplating
Finish and/or surface treatment Plain shall be in
If different electroplating is required or accordance with
if other finishes are needed, they shall JIS B 1044.
be as agreed between the parties
concerned with delivery.

Limits for surface defects shall be in

accordance with JIS B 1042.

Acceptability For acceptance procedure, see JIS B 1091.

Note (5): For other strength divisions, see JIS B 1052 for steel nuts and JIS B 1054-2 for stainless steel nuts, respectively.

Designation of products
Example
Product Hexagon nut with thread M12, strength division 8, and style
Designation Hexagon nut-style 1, JIS B 1181-ISO 4032-M12-8