Strain Hardened 321 Titanium Stabilized High-Strength Continuous & Double-End Studs
ASTM A320 Grade B8T Class 2 combine titanium stabilization with strain hardening to deliver elevated strength in weldable austenitic stainless steel. These cold-worked 321 studs achieve 125 ksi tensile and 100 ksi yield strength in sizes 3/4 in. [20 mm] and under (100 ksi tensile and 50 ksi yield over 1 1/4 to 1 1/2 in. [32 to 40 mm]) for high-performance flanged connections subject to thermal cycling. B8T Class 2 are specified for flanged joints in pressure vessels, valves, and process piping in low-temperature service where welded construction, high clamping force, and resistance to sensitization are required together.
| Grade Symbol | UNS Designation | C, max | Mn, max | P, max | S, max | Si, max | Ni | Cr | Ti | N | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A320 B8T | S32100(321) | Range,% | 0.08 | 2.00 | 0.045 | 0.030, max | 1.00 | 9.0- 12.0 | 17.0- 19.0 | 5 × (C+N) min -0.7 max | 010, max |
| Product Variation, % Over or Under | 0.01 over | 0.04 over | 0.010 over | 0.005 over | 0.05 over | 0.15 | 0.20 | 0.05 under | 1 | ||
| 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 B8T 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 |
