Grade 8 Hex Cap Screws
The high-strength alloy bolt: quenched and tempered alloy steel at 150 ksi tensile and 130 ksi yield in all sizes to 4 in. — Grade 8 in SAE terms, A354 BD in ASTM terms.
Fully threaded hex heads with a robust design for industrial applications. Manufactured to ASME B18.2.1 with washer-face bearing surface, in all stocked grades.
SAE J429 Grade 8 and ASTM A354 Grade BD describe the same class of product: an alloy steel bolt or stud quenched and tempered to 150 ksi tensile and 130 ksi yield, at 33 to 38 HRC. Grade 8 is marked with six radial lines and runs to 1½ in.; A354 BD covers sizes to 4 in. with a nickel-chromium-molybdenum requirement above 2¼ in. and is the specification industrial and structural orders are written to.
Hot-shot or plant down? Call 832-446-3442, answered 24/7.
What Grade 8 must meet.
| Grade / condition and size | Tensile strength, min (ksi) | Yield or proof, min (ksi) | Elongation, min (%) | Reduction of area, min (%) | Hardness |
|---|---|---|---|---|---|
| Grade BD — all sizes to 4 in. | 150 (173 max) | 130 | 14 | 40 | 33–38 HRC (311–352 HBW) |
Values per ASTM A354-17 Tables 2 and 4 (verified against the specification). Confirm the edition called out on your purchase order with our estimating team. Full-size tensile and proof loads by thread size are in Table 3 of the specification.
Quenched in liquid from above the transformation temperature and tempered at 800 °F minimum. Fasteners heat treated after threading are oil quenched. Plated parts are baked for hydrogen embrittlement relief.
Full Grade 8 / A354 BD data sheet: chemistry, physical properties and standards →
Made to standard or to your drawing.
- Heavy equipment and mining machinery
- Crane, hoist and lifting hardware
- High-strength studs and tie rods
- Anchor and structural bolting over 1½ in. where A490 cannot be used
- Automotive and driveline bolting