| Screw Thread | 2-1/2 | ||
| D | 2.5000 | ||
| P | 4 | ||
| B | Min | L≤10 | 5.250 |
| B | Min | 10＜L≤16 | 5.500 |
| B | Min | L＞16 | 6.000 |
| U | Max | UNC | 0.500 |
| U | Max | UNF | None |
| U | Max | BUN | 0.250 |
| Ds | Max | 2.5000 | |
| Ds | Min | UNC | 2.473 |
| Ds | Min | UNF | None |
| Ds | Min | BUN | 2.483 |
| Ds1 | Max | UNC | 2.473 |
| Ds1 | Max | UNF | None |
| Ds1 | Max | BUN | 2.483 |
| Ds1 | Min | UNC | 2.324 |
| Ds1 | Min | UNF | None |
| Ds1 | Min | BUN | 2.408 |