Nut Dimensions - Hex / Jam / Heavy Hex
Printable shop wall chart: Nut Dimensions - Hex / Jam / Heavy Hex. Free letter-size PDF to print and post at the counter; 25 x 36 inch poster version available.
Inch, ASME B18.2.2 (in)
| Size | Hex across flats | Hex thickness | Jam thickness | Heavy hex across flats | Heavy hex thickness |
|---|---|---|---|---|---|
| 1/4 | 7/16 | 7/32 | 5/32 | 1/2 | 15/64 |
| 5/16 | 1/2 | 17/64 | 3/16 | 9/16 | 19/64 |
| 3/8 | 9/16 | 21/64 | 7/32 | 11/16 | 23/64 |
| 7/16 | 11/16 | 3/8 | 1/4 | 3/4 | 27/64 |
| 1/2 | 3/4 | 7/16 | 5/16 | 7/8 | 31/64 |
| 5/8 | 15/16 | 35/64 | 3/8 | 1-1/16 | 39/64 |
| 3/4 | 1-1/8 | 41/64 | 27/64 | 1-1/4 | 47/64 |
| 7/8 | 1-5/16 | 3/4 | 31/64 | 1-7/16 | 55/64 |
| 1 | 1-1/2 | 55/64 | 35/64 | 1-5/8 | 63/64 |
Metric nut height m (max), mm
| Size | ISO 4032 style 1 | ISO 4033 style 2 (high) | ISO 4035 thin (jam) |
|---|---|---|---|
| M6 | 5.2 | 5.7 | 3.2 |
| M8 | 6.8 | 7.5 | 4 |
| M10 | 8.4 | 9.3 | 5 |
| M12 | 10.8 | 12 | 6 |
| M16 | 14.8 | 16.4 | 8 |
| M20 | 18 | 20.3 | 10 |
| M24 | 21.5 | 23.9 | 12 |
Heavy hex is both an ASME B18.2.2 nut style and the required structural nut under ASTM F3125 / A563: it is not just a thicker nut. Metric across flats follow ISO 4032 (see wrench chart).
These tables carry the same figures as the printed sheet below.
The printed sheet
25 x 36 inch poster version
For the full-size shop poster, tell us where to send it.
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Text version of this sheet
HEX NUT
JAM NUT
HEAVY HEX NUT
ASME B18.2.2 (inch) and ISO 4032 / 4033 / 4035 (metric)
Inch, ASME B18.2.2 (in)
Size
Hex across flats
Hex thickness
Jam thickness
Heavy hex across flats
Heavy hex thickness
1/4
7/16
7/32
5/32
1/2
15/64
5/16
1/2
17/64
3/16
9/16
19/64
3/8
9/16
21/64
7/32
11/16
23/64
7/16
11/16
3/8
1/4
3/4
27/64
1/2
3/4
7/16
5/16
7/8
31/64
5/8
15/16
35/64
3/8
1-1/16
39/64
3/4
1-1/8
41/64
27/64
1-1/4
47/64
7/8
1-5/16
3/4
31/64
1-7/16
55/64
1
1-1/2
55/64
35/64
1-5/8
63/64
Metric nut height m (max), mm
Size
ISO 4032 style 1
ISO 4033 style 2 (high)
ISO 4035 thin (jam)
M6
5.2
5.7
3.2
M8
6.8
7.5
4
M10
8.4
9.3
5
M12
10.8
12
6
M16
14.8
16.4
8
M20
18
20.3
10
M24
21.5
23.9
12
Heavy hex is both an ASME B18.2.2 nut style and the required structural nut under ASTM F3125 / A563: it is not just a thicker nut. Metric across flats follow ISO 4032 (see wrench chart).
The Fastener App | TheFastenerApp.com
Fastener Guide reference FG-DA1514 · thefastenerapp.com/fastener-guide/wall-charts/nut-dimensions-hex-jam-heavy-hex · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.
