Thin height Heavy Hex
| Part Number | Nominal Size | F | G | H | I | |
| Across Flats | Across Corner | Height | Side Height | |||
| Max | Min | |||||
| 21FKC-420 | 1/4-20 | .502 | .492 | .552 | .290 | .053 |
| 21FK-518 | 5/16-18 | .564 | .553 | .622 | .321 | .087 |
| 21FK-616 | 3/8-16 | .627 | .616 | .596 | .384 | .085 |
| 21FK-714 | 7/16-14 | .752 | .741 | .837 | .446 | .101 |
| 21FK-813 | 1/2-13 | .814 | .803 | .907 | .509 | .101 |
| 21FKC-912 | 9/16-12 | .940 | .928 | 1.051 | .571 | .104 |
| 21FK-1011 | 5/8-11 | 1.002 | .990 | 1.119 | .634 | .116 |
| 21FK-1210 | 3/4-10 | 1.127 | 1.115 | 1.26 | .759 | .121 |
| 21FK-1409 | 7/8-9 | 1.314 | 1.301 | 1.47 | .884 | .163 |
| 21FK-1608 | 1-8 | 1.502 | 1.489 | 1.682 | 1.009 | .207 |
| 21FK-1807 | 1-1/8-7 | 1.814 | 1.801 | 2.038 | 1.134 | .202 |
| 21FK-2007 | 1-1/4-7 | 2.002 | 1.988 | 2.250 | 1.259 | .287 |
| 21FK-2206 | 1-3/8-6 | 2.190 | 2.176 | 2.484 | 1.384 | .300 |
| 21FK-2406 | 1-1/2-6 | 2.377 | 2.363 | 2.697 | 1.509 | .326 |
Dimensions per SPS Technologies
Disclaimer: The dimensions listed are for reference only. Sizes not listed may be available off the shelf or can be manufactured to customer requirements.