Can coupling nuts be made in custom lengths?

Hex and heavy hex coupling nuts can be made in custom lengths. Depending on the size and grade, however, there may be an extended lead time associated with doing that. Off-the-shelf coupling nut lengths have fairly few options for a given diameter. As long as the coupling nut is long enough to achieve the desired thread engagement, the lack of length options may not be an issue. However, there are certain applications where the coupling nut will need to be longer than standard. In this case, the coupling nut will need to be custom machined, and if made to a higher strength grade, such as A194 2H or A563 DH, will then need to go through a heat treating process.

Below are two charts detailing the standard dimensions of coupling nuts per ASME B18.2.2 2010, which should be readily available in the marketplace. If the coupling nut that you are looking for is longer than what is shown, it will likely need to be custom manufactured. Custom coupling nuts with larger or smaller hex dimensions as well as galvanized coatings can also be manufactured. Contact Portland Bolt for any of your coupling nut requirements and the fasteners that are being coupled together.

Finished Hex Coupler Dimensions

Click table to show drawingHex Coupling Nut
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
12 1116 0.688 0.663 0.794 0.756 134 1.760 1.690 12338 17525
58 1316 0.813 0.782 0.939 0.891 218 2.135 2.067 12559 18195
34 1 1.000 0.963 1.155 1.097 214 2.260 2.190 12557 17526
78 114 1.250 1.212 1.443 1.382 212 2.510 2.440 12558 19504
1 138 1.375 1.325 1.588 1.511 234 2.760 2.690 - 18494
118 112 1.500 1.450 1.732 1.653 3 3.010 2.940 18394 -
114 158 1.625 1.575 1.876 1.825 3 3.010 2.940 18994 17529
112 2 2.000 1.950 2.309 2.275 312 3.510 3.440 - -
Dimensions per ASME B18.2.2 2010
Some dimensions may vary by supplier

Heavy Hex Coupler Dimensions

Click table to show drawingHex Coupling Nut
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
12 78 0.875 0.850 1.010 0.969 112 - - 17541 17542
58 1116 1.062 1.031 1.227 1.175 178 - - 17543 17544
34 114 1.250 1.212 1.443 1.382 214 - - 17528 17527
78 1716 1.438 1.394 1.660 1.589 258 - - 19501 19502*
1 158 1.625 1.575 1.876 1.796 3 - - 12344 12343
118 11316 1.812 1.756 2.093 2.002 338 - - 12348 12349
114 2 2.000 1.938 2.309 2.209 334 - - 17547 17548
112 238 2.375 2.300 2.742 2.622 412 - - 17551 17552
158 2916 2.562 2.481 2.959 2.828 478 4.91 4.83 - -
134 234 2.750 2.662 3.175 3.035 514 5.29 5.21 17553 17554
178 21516 2.938 2.844 3.392 3.242 558 5.67 5.58 - -
2 318 3.125 3.025 3.608 3.449 6 6.04 5.95 17555 17556
214 312 3.500 3.388 4.041 3.862 634 6.80 6.70 - -
212 378 3.875 3.750 4.474 4.275 712 7.55 7.44 - -
234 414 4.250 4.112 4.907 4.688 814 8.31 8.19 - -
3 458 4.625 4.475 5.340 5.102 9 9.06 8.94 - -
314 5 5.000 4.838 5.774 5.515 934 9.81 9.68 - -
312 538 5.375 5.200 6.207 5.928 1012 10.57 10.43 - -
334 534 5.750 5.562 6.640 6.341 1114 11.32 11.17 - -
4 618 6.125 5.925 7.073 6.755 12 12.08 11.92 - -
412 678 6.875 6.650 7.939 7.581 1312 - - - -
5 758 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.
Written

4 comments

    @Tim- We could likely do that, yes. We would need drawing with your specific needs, and then, if it is a feasible part, we could provide you with a formal quote.

    are you able to do coupling nuts with different thread pitch on each side of coupler ?

    kinda of like a reducer idea.

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