Hex Coupling Nuts
Hex couplers are used to connect two pieces of threaded material. Hex and heavy hex couplers are threaded right hand. If a right hand-left hand coupler is needed, consider using a sleeve nut.
See our nut compatibility chart to determine the compatible hex coupler for a specific grade of bolt. Since hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized couplers are tapped oversize to compensate for the corrosion resistant coating on the bolts.
STOCK
Diameters: 1/2" – 6"
Origin: Domestic and import
Finish: Black and hot-dip galvanized
Grades: A563 (grades A, C, and DH), A194 grade 2H
Finished Hex Coupler Pattern
| Nominal Size |
F |
C |
H |
| Width Across Flats |
Width Across Corners |
Thickness |
| Basic |
Max |
Min |
Max |
Min |
Basic |
Max |
Min |
| 1/2 |
3/4 |
.75 |
.736 |
.866 |
.839 |
1-1/2 |
1.51 |
1.49 |
| 5/8 |
15/16 |
.938 |
.922 |
1.083 |
1.051 |
1-7/8 |
1.89 |
1.86 |
| 3/4 |
1-1/8 |
1.125 |
1.088 |
1.299 |
1.240 |
2-1/4 |
2.27 |
2.22 |
| 7/8 |
1-5/16 |
1.312 |
1.269 |
1.516 |
1.447 |
2-5/8 |
2.65 |
2.60 |
| 1 |
1-1/2 |
1.500 |
1.450 |
1.732 |
1.653 |
3 |
3.03 |
2.97 |
| 1-1/8 |
1-11/16 |
1.688 |
1.631 |
1.949 |
1.859 |
3-3/8 |
3.40 |
3.34 |
| 1-1/4 |
1-7/8 |
1.875 |
1.812 |
2.165 |
2.066 |
3-3/4 |
3.78 |
3.71 |
| 1-3/8 |
2-1/16 |
2.062 |
1.994 |
2.382 |
2.273 |
4-1/8 |
4.16 |
4.09 |
| 1-1/2 |
2-1/4 |
2.250 |
2.175 |
2.598 |
2.480 |
4-1/2 |
4.54 |
4.46 |
Dimensions per IFI-128 2000 and ASME B18.2.2 page
D-22
Heavy Hex Coupler Pattern
| Nominal Size |
F |
C |
H |
| Width Across Flats |
Width Across Corners |
Thickness |
| Basic |
Max |
Min |
Max |
Min |
Basic |
Max |
Min |
| 1-5/8 |
2-9/16 |
2.562 |
2.481 |
2.959 |
2.828 |
4-7/8 |
4.91 |
4.83 |
| 1-3/4 |
2-3/4 |
2.750 |
2.662 |
3.175 |
3.035 |
5-1/4 |
5.29 |
5.21 |
| 1-7/8 |
2-15/16 |
2.938 |
2.844 |
3.392 |
3.242 |
5-5/8 |
5.67 |
5.58 |
| 2 |
3-1/8 |
3.125 |
3.025 |
3.608 |
3.449 |
6 |
6.04 |
5.95 |
| 2-1/4 |
3-1/2 |
3.500 |
3.388 |
4.041 |
3.862 |
6-3/7 |
6.80 |
6.70 |
| 2-1/2 |
3-7/8 |
3.875 |
3.750 |
4.474 |
4.275 |
7-1/2 |
7.55 |
7.44 |
| 2-3/4 |
4-1/4 |
4.250 |
4.112 |
4.907 |
4.688 |
8-1/4 |
8.31 |
8.19 |
| 3 |
4-5/8 |
4.625 |
4.475 |
5.340 |
5.102 |
9 |
9.06 |
8.94 |
| 3-1/4 |
5 |
5.000 |
4.838 |
5.774 |
5.515 |
9-3/4 |
9.81 |
9.68 |
| 3-1/2 |
5-3/8 |
5.375 |
5.200 |
6.207 |
5.928 |
10-1/2 |
10.57 |
10.43 |
| 3-3/4 |
5-3/4 |
5.750 |
5.562 |
6.640 |
6.341 |
11-1/4 |
11.32 |
11.17 |
| 4 |
6-1/8 |
6.125 |
5.925 |
7.073 |
6.755 |
12 |
12.08 |
11.92 |
| 4-1/2 |
6-7/8 |
6.875 |
6.650 |
7.939 |
7.581 |
13-1/2 |
– |
– |
| 5 |
7-5/8 |
7.625 |
7.375 |
8.805 |
8.408 |
15 |
– |
– |
Dimensions per ASME B18.2.2 1987 (R 1999)
Note: Dimension may vary based on available raw material