ASTM A193 Grade B7 stud bolt chart: thread, tensile stress area, 50 % yield preload (kN), dry-thread torque (Nm) and the ASME B16.5 flange class / NPS pairing for stud sizes 1/2 in through 2-1/2 in. B7 is the default flange stud in the ASME B16.5 / B16.47 range — 4140/4142 alloy-steel, Class 2A UN thread, used with ASTM A194 Grade 2H heavy-hex nuts.
ASTM A193 Grade B7 is the default flange stud in the ASME B16.5 / B16.47 range — an alloy-steel bolt in the 4140/4142 family, quench-and-tempered to 105 ksi (724 MPa) tensile strength and 105 ksi (724 MPa) yield up to 2 in, dropping to 100 / 95 / 75 ksi as the diameter steps up. The stud is threaded to Class 2A UN across the whole length and used with two ASTM A194 Grade 2H heavy-hex nuts.
| Stud | Pitch | Tensile A (in²) | 50 % Fy (kN) | Torque dry (Nm) | Flange pairing (ASME B16.5) |
|---|---|---|---|---|---|
| 1/2 in | 13 UNC | 0.1419 | 45 | 140 | ASME 150 NPS 3–8, EN PN10 DN15–100 |
| 5/8 in | 11 UNC | 0.2260 | 71 | 270 | ASME 150 NPS 4–10, ASME 300 NPS 1–6 |
| 3/4 in | 10 UNC | 0.3345 | 106 | 475 | ASME 150 NPS 6–24, ASME 300 NPS 2–10, ASME 600 NPS 1–8 |
| 7/8 in | 9 UNC | 0.4617 | 146 | 760 | ASME 300 NPS 4–12, ASME 600 NPS 3–10 |
| 1 in | 8 UNC | 0.6057 | 191 | 1130 | ASME 300 NPS 8–16, ASME 600 NPS 5–14, ASME 900 NPS 2–8 |
| 1-1/8 in | 8 UN | 0.7906 | 249 | 1580 | ASME 300 NPS 12–24, ASME 600 NPS 8–18, ASME 900 NPS 4–14 |
| 1-1/4 in | 8 UN | 0.9691 | 305 | 2140 | ASME 300 NPS 14–24, ASME 600 NPS 10–24, ASME 900 NPS 6–16 |
| 1-3/8 in | 8 UN | 1.1730 | 370 | 2830 | ASME 600 NPS 14–24, ASME 900 NPS 8–20 |
| 1-1/2 in | 8 UN | 1.4030 | 442 | 3670 | ASME 600 NPS 16–24, ASME 900 NPS 10–24, ASME 1500 NPS 3–8 |
| 1-5/8 in | 8 UN | 1.6600 | 523 | 4660 | ASME 600 NPS 18–24, ASME 900 NPS 12–24 |
| 1-3/4 in | 8 UN | 1.9430 | 612 | 5810 | ASME 900 NPS 16–24, ASME 1500 NPS 8–14 |
| 1-7/8 in | 8 UN | 2.2500 | 709 | 7130 | ASME 600 NPS 24, ASME 900 NPS 20–24 |
| 2 in | 8 UN | 2.5800 | 813 | 8640 | ASME 1500 NPS 10–18 |
| 2-1/4 in | 8 UN | 3.2500 | 1020 | 12200 | ASME 1500 NPS 14–24 |
| 2-1/2 in | 8 UN | 4.0000 | 1260 | 16800 | ASME 1500 NPS 16–24, ASME 2500 NPS 6–12 |
Torque values are for K = 0.20 dry threads at 50 % of specified minimum yield. Lubricated with anti-seize (K = 0.16): multiply the torque by ~0.75. Never re-use a B7 stud loaded to 50 % Fy — the elastic history changes the K factor.