| Screw Thread | 3-3/4 | ||
| D | 3.7500 | ||
| P | 4 | ||
| B | Min | L≤10 | None |
| B | Min | 10＜L≤16 | 8.000 |
| B | Min | L＞16 | 8.500 |
| U | Max | UNC | 0.500 |
| U | Max | UNF | None |
| U | Max | BUN | 0.250 |
| Ds | Max | 3.7500 | |
| Ds | Min | UNC | 3.723 |
| Ds | Min | UNF | None |
| Ds | Min | BUN | 3.732 |
| Ds1 | Max | UNC | 3.723 |
| Ds1 | Max | UNF | None |
| Ds1 | Max | BUN | 3.732 |
| Ds1 | Min | UNC | 3.573 |
| Ds1 | Min | UNF | None |
| Ds1 | Min | BUN | 3.657 |