B8M Cl.2Stud bolt
ASTM A193 Grade B8M Class 2
Strain-hardened 316. Combines the chloride resistance of B8M with useful bolt load — the usual choice for small-diameter seawater flanges that would need oversized studs in Class 1.
- Base material
- Austenitic stainless steel, AISI 316
- Heat treatment condition
- Solution treated then strain hardened
- Hardness, max
- 321 HBW / 35 HRC maximum
Service temperature
-254 °C+400 °C−273+900 °C
As with B8 Class 2, not available above 1½ in and not suitable where the cold work would be annealed out by service temperature.
Chemical composition
| Element | Min (% by weight) | Max (% by weight) |
|---|---|---|
| C | — | 0.08 |
| Mn | — | 2.00 |
| Si | — | 1.00 |
| P | — | 0.045 |
| S | — | 0.030 |
| Cr | 16.0 | 18.0 |
| Ni | 10.0 | 14.0 |
| Mo | 2.00 | 3.00 |
Mechanical properties
| Diameter | Tensile strength, min | Yield strength, min | Elongation, min | Reduction of area, min |
|---|---|---|---|---|
| ≤ ¾ in (≤ M20) | 760 MPa (110 ksi) | 655 MPa (95 ksi) | 15 % | 45 % |
| > ¾ – 1 in (M20–M24) | 690 MPa (100 ksi) | 550 MPa (80 ksi) | 20 % | 45 % |
| > 1 – 1¼ in (M24–M30) | 655 MPa (95 ksi) | 450 MPa (65 ksi) | 25 % | 45 % |
| > 1¼ – 1½ in (M30–M36) | 620 MPa (90 ksi) | 345 MPa (50 ksi) | 30 % | 45 % |
Matching nuts
Recommended coatings
Equivalent grades
- AISI 316 cold worked
- EN 1.4401
- ISO 3506 A4-70 (gan tuong duong)
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