Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASTM A320 Grade B8 Class 2
Strain Hardened 304 Stainless Steel High-Strength Continuous & Double-End Studs
ASTM A320 Grade B8 Class 2 undergo cold strain hardening to achieve significantly elevated mechanical properties for demanding bolting applications. These 304 stainless steel studs deliver 125 ksi tensile strength and 100 ksi yield strength in diameters up to 3/4 inch, providing superior clamping force in flanged connections. While the strain hardening process increases magnetic permeability, B8 Class 2 remain the preferred choice for high-pressure vessel joints, heat exchanger flanges, and structural connections where higher preload and thread engagement strength are critical.
ASTM A320/A320M Grade B8 Properties
ASTM A320/A320M Grade B8 Chemical Requirements
Austenitic Steels
| Grade Symbol | UNS Designation | C, max | Mn, max | P, max | S, max | Si, max | Ni | Cr | |
|---|---|---|---|---|---|---|---|---|---|
| ASTM A320 B8 | S30400(304) | Range,% | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 8.0-11.0 | 18.0 - 20.0 |
ASTM A320/A320M Grade B8 Mechanical Requirements
| Grade and Class | Diameter, in. [mm] | Heat Treatment | Tensile Strength, min, ksi [MPa] | Yield Strength, min, ksi [MPa] (0.2 % offset) | Elongation in 2 in. or 50 mm, min, % | Reduction of Area, min, % | Hardness, max |
|---|---|---|---|---|---|---|---|
| ASTM A320 B8 Class 2 | 3/4 [20] and under | carbide solution treated and strain hardened | 125 [860] | 100 [690] | 12 | 35 | 321 HBW or 35 HRC |
| over 3/4 to 1 [20 to 25], incl | 115 [795] | 80 [550] | 15 | 30 | 321 HBW or 35 HRC | ||
| over 1 to 11/4 [25 to 32], incl | 105 [725] | 65 [450] | 20 | 35 | 321 HBW or 35 HRC | ||
| over 11/4 to 11/2 [32 to 40], inclA | 100 [690] | 50 [345] | 28 | 45 | 321 HBW or 35 HRC |
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