IFI 128 Hex Coupling Nuts
IFI-128 covers hex coupling nuts used to join threaded rods or studs. Drawing marks across-flats width, across-corners width and length.
Selected coupling-nut dimensions (in)
| Thread | F basic | F max | F min | G max | G min | H basic | H max | H min |
|---|---|---|---|---|---|---|---|---|
| 1/4 | 3/8 | .375 | .365 | .433 | .416 | 3/4 | .76 | .74 |
| 5/16 | 1/2 | .500 | .489 | .577 | .557 | 15/16 | .95 | .93 |
| 3/8 | 9/16 | .562 | .551 | .650 | .628 | 1-1/8 | 1.13 | 1.11 |
| 1/2 | 3/4 | .750 | .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 |
IFI-128 is withdrawn and cross-referenced to ASME B18.2.2. Selected inch-series values; verify the governing edition and thread engagement.