Female-female hex standoffs are threaded fasteners that have female threads at each end so components can be screwed into both sides to connect and space materials. Their hexagonal shape allows for a firm grip with a wrench to hold the standoff in place during assembly. They are often used as a coupling nut to join male threaded parts.
| Screw Thread d | Φ2 | Φ2.5 | Φ3 | Φ3.5 | Φ4 | Φ4.5 | Φ5 | Φ6 | Φ8 | Φ10 | Φ12 | Φ13 | |||
| d | Before mounting | max | 2.4 | 2.9 | 3.5 | 4 | 4.6 | 5.1 | 5.6 | 6.7 | 8.8 | 10.8 | 12.8 | 13.8 | |
| min | 2.3 | 2.8 | 3.3 | 3.8 | 4.4 | 4.9 | 5.4 | 6.4 | 8.5 | 10.5 | 12.5 | 13.5 | |||
| d1 | Before mounting | ref. | 1.9 | 2.3 | 2.7 | 3.1 | 3.4 | 3.9 | 4.4 | 4.9 | 7 | 8.5 | 10.5 | 11 | |
| h | 0.2 | 0.25 | 0.3 | 0.35 | 0.5 | 0.5 | 0.5 | 0.75 | 0.75 | 1 | 1 | 1.2 | |||
| Minimum Double Shear,kN | 1.5 | 2.4 | 3.5 | 4.6 | 8 | 8.8 | 10.4 | 18 | 24 | 40 | 48 | 66 | |||
| Screw Thread d | Φ14 | Φ16 | Φ18 | Φ20 | Φ21 | Φ25 | Φ28 | Φ30 | Φ35 | Φ40 | Φ45 | Φ50 | |||
| d | Before mounting | max | 14.8 | 16.8 | 18.9 | 20.9 | 21.9 | 25.9 | 28.9 | 30.9 | 35.9 | 40.9 | 45.9 | 50.9 | |
| min | 14.5 | 16.5 | 18.5 | 20.5 | 21.5 | 25.5 | 28.5 | 30.5 | 35.5 | 40.5 | 45.5 | 50.5 | |||
| d1 | Before mounting | ref. | 11.5 | 13.5 | 15 | 16.5 | 17.5 | 21.5 | 23.5 | 25.5 | 28.5 | 32.5 | 37.5 | 40.5 | |
| h | 1.5 | 1.5 | 1.7 | 2 | 2 | 2 | 2.5 | 2.5 | 3.5 | 4 | 4 | 5 | |||
| Minimum Double Shear,kN | 84 | 98 | 126 | 158 | 168 | 202 | 280 | 302 | 490 | 634 | 720 | 1000 | |||