Carbide Solution Treated 303 Free-Machining Continuous & Double-End Studs
ASTM A320 Grade B8F Class 1 are produced from free-machining Type 303 (UNS S30300) or Type 303Se (UNS S30323) stainless steel (Table 3) with carbide solution treatment. These Class 1 studs provide 75 ksi minimum tensile strength and 30% elongation, with maximum hardness of 223 HBW or 96 HRB (241 HBW or 100 HRB permitted for sizes 3/4 in. [20 mm] and smaller). Class 1 Grade B8F is exempt from impact testing only above -325°F [-200°C] (6.2.1.1); it is not in the -425°F list. B8F Class 1 suit low temperature bolting where a free-machining grade is wanted.
| Grade Symbol | UNS Designation | C, max | Mn, max | P, max | S, max | Si, max | Ni | Cr | Se | |
|---|---|---|---|---|---|---|---|---|---|---|
| ASTM A320 B8F | S30300(303) | Range,% | 0.15 | 2.00 | 0.20 | 00.15, min | 1.00 | 8.0 - 10.0 | 17.0- 19.0 | 0.15-0.35 |
| Product Variation, % Over or Under | 0.01 over | 0.04 over | 0.010 over | 0.20 | 0.05 over | 0.10 | 0.20 | ... | ||
| 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 B8F : Class 1 | All diameters | carbide solution treated | 75 [515] | 30 [205] | 30 | 50 | 223 HBWDor 96 HRB |
