Hex couplers are used to connect two externally threaded fasteners. Both ends of hex and heavy hex couplers are threaded right hand. If a right hand-left hand coupler is needed, consider using a sleeve nut. Most coupling nuts connect like-diameter fasteners, but reducer coupling nuts can be manufactured to connect products with different diameters. A sight hole can be added to the centerline of the coupling nut to verify that the externally threaded fastener has been fully engaged.
We’re excited to announce a significant expansion to our manufacturing capabilities by manufacturing heavy hex coupling nuts in-house! Our recent investment in a state-of-the-art CNC lathe makes this new offering possible. This expands the portfolio of products we can manufacture, meet lead-time requirements, and accommodate rush orders. If we don’t stock it, we can make it.
See our nut compatibility chart to determine the recommended 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.
Domestic Heavy Hex Coupling Nut Stock
| Part Numbers | |||||
|---|---|---|---|---|---|
| Diameter | Origin | Finishes | Grades | Plain | Galvanized |
| 3/4" | Domestic | Plain, hot-dip galvanized | A563 grade DH, A194 Grade 2H | 17528 | 17527 |
| 7/8" | Domestic | Plain, hot-dip galvanized | A563 grade DH | 19501 | 19502 |
| 1" | Domestic | Plain, hot-dip galvanized | A563 grade DH | 12344 | 12343 |
| 1-1/4" | Domestic | Plain, hot-dip galvanized | A563 grade DH, A194 Grade 2H | 17547 | 17548 |
| 1-1/2" | Domestic | Plain, hot-dip galvanized | A563 grade DH | 17551 | 17552 |
Import Hex Coupling Nut Stock
| Part Numbers | |||||
|---|---|---|---|---|---|
| Diameter | Origin | Finishes | Grades | Plain | Galvanized |
| 1/2" | Import | Plain, hot-dip galvanized | A563 grade A | 12338 | 17525 |
| 5/8" | Import | Plain, hot-dip galvanized | A563 grade A | 12559 | 18195 |
| 7/8" | Import | Plain, hot-dip galvanized | A563 grade A | 12559 | 18195 |
| 1" | Import | Plain, hot-dip galvanized | A563 grade A | 12558 | 19504 |
| 1.5" | Import | Plain, hot-dip galvanized | A563 grade A | 18995 | |
Available
Diameters: 1/2″ – 6″
Origin: Domestic and import
Finish: Plain and hot-dip galvanized
Grades: A563 (grades A, C, and DH), A194 grade 2H
Dimensions
Finished Hex Coupling Nut Pattern
| Nominal Size | F | C | H | Part Numbers | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Width Across Flats | Width Across Corners | Length/Thickness | Import | |||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | Plain | Galvanized | |
| 1⁄2 | 11⁄16 | 0.688 | 0.663 | 0.794 | 0.756 | 13⁄4 | 1.760 | 1.690 | 12338 | 17525 |
| 5⁄8 | 13⁄16 | 0.813 | 0.782 | 0.939 | 0.891 | 21⁄8 | 2.135 | 2.067 | 12559 | 18195 |
| 3⁄4 | 1 | 1.000 | 0.963 | 1.155 | 1.097 | 21⁄4 | 2.260 | 2.190 | 12557 | 17526 |
| 7⁄8 | 11⁄4 | 1.250 | 1.212 | 1.443 | 1.382 | 21⁄2 | 2.510 | 2.440 | 12558 | 19504 |
| 1 | 13⁄8 | 1.375 | 1.325 | 1.588 | 1.511 | 23⁄4 | 2.760 | 2.690 | - | 18494 |
| 11⁄8 | 11⁄2 | 1.500 | 1.450 | 1.732 | 1.653 | 3 | 3.010 | 2.940 | 18394 | - |
| 11⁄4 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.825 | 3 | 3.010 | 2.940 | 18994 | 17529 |
| 11⁄2 | 2 | 2.000 | 1.950 | 2.309 | 2.275 | 31⁄2 | 3.510 | 3.440 | - | - |
| Dimensions per ASME B18.2.2 2010 | ||||||||||
Heavy Hex Coupling Nut Pattern
| Nominal Size | F | C | H | Part Numbers | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Width Across Flats | Width Across Corners | Thickness | A563DH Domestic | |||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | Plain | Galvanized | |
| 1⁄2 | 7⁄8 | 0.875 | 0.850 | 1.010 | 0.969 | 11⁄2 | - | - | 17541 | 17542 |
| 5⁄8 | 11⁄16 | 1.062 | 1.031 | 1.227 | 1.175 | 17⁄8 | - | - | 17543 | 17544 |
| 3⁄4 | 11⁄4 | 1.250 | 1.212 | 1.443 | 1.382 | 21⁄4 | - | - | 17528 | 17527 |
| 7⁄8 | 17⁄16 | 1.438 | 1.394 | 1.660 | 1.589 | 25⁄8 | - | - | 19501 | 19502* |
| 1 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.796 | 3 | - | - | 12344 | 12343 |
| 11⁄8 | 113⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 33⁄8 | - | - | 12348 | 12349 |
| 11⁄4 | 2 | 2.000 | 1.938 | 2.309 | 2.209 | 33⁄4 | - | - | 17547 | 17548 |
| 11⁄2 | 23⁄8 | 2.375 | 2.300 | 2.742 | 2.622 | 41⁄2 | - | - | 17551 | 17552 |
| 15⁄8 | 29⁄16 | 2.562 | 2.481 | 2.959 | 2.828 | 47⁄8 | 4.91 | 4.83 | - | - |
| 13⁄4 | 23⁄4 | 2.750 | 2.662 | 3.175 | 3.035 | 51⁄4 | 5.29 | 5.21 | 17553 | 17554 |
| 17⁄8 | 215⁄16 | 2.938 | 2.844 | 3.392 | 3.242 | 55⁄8 | 5.67 | 5.58 | - | - |
| 2 | 31⁄8 | 3.125 | 3.025 | 3.608 | 3.449 | 6 | 6.04 | 5.95 | 17555 | 17556 |
| 21⁄4 | 31⁄2 | 3.500 | 3.388 | 4.041 | 3.862 | 63⁄4 | 6.80 | 6.70 | - | - |
| 21⁄2 | 37⁄8 | 3.875 | 3.750 | 4.474 | 4.275 | 71⁄2 | 7.55 | 7.44 | - | - |
| 23⁄4 | 41⁄4 | 4.250 | 4.112 | 4.907 | 4.688 | 81⁄4 | 8.31 | 8.19 | - | - |
| 3 | 45⁄8 | 4.625 | 4.475 | 5.340 | 5.102 | 9 | 9.06 | 8.94 | - | - |
| 31⁄4 | 5 | 5.000 | 4.838 | 5.774 | 5.515 | 93⁄4 | 9.81 | 9.68 | - | - |
| 31⁄2 | 53⁄8 | 5.375 | 5.200 | 6.207 | 5.928 | 101⁄2 | 10.57 | 10.43 | - | - |
| 33⁄4 | 53⁄4 | 5.750 | 5.562 | 6.640 | 6.341 | 111⁄4 | 11.32 | 11.17 | - | - |
| 4 | 61⁄8 | 6.125 | 5.925 | 7.073 | 6.755 | 12 | 12.08 | 11.92 | - | - |
| 41⁄2 | 67⁄8 | 6.875 | 6.650 | 7.939 | 7.581 | 131⁄2 | - | - | - | - |
| 5 | 75⁄8 | 7.625 | 7.375 | 8.805 | 8.408 | 15 | - | - | - | - |
| Heavy coupler dimensions are not defined by ASME 18.2.2. The width across the flats and corners match the dimensions of a heavy hex nut. * 7/8" Galvanized Couplers are 3" long. | ||||||||||