Materials

ASTM A354 Grade BC

• Manufacturing Considerations:

  • Medium-carbon alloy steel, quenched and tempered.

  • Machines well and responds consistently to controlled heat treatment.

  • Typically produced in diameters up to 4 inches.

• Performance in Fasteners:

  • Minimum tensile strength ~125 ksi (comparable to A193 Grade B7).

  • Strong and tough, making it suitable for bolts, studs, and cap screws in critical equipment.

  • Good for general high-strength bolting applications where elevated temperature or severe corrosion is not the primary concern.

• Common Uses:

  • Heavy construction equipment, turbines, pumps, and pressure vessel assemblies.

ASTM A354 Grade BD

• Manufacturing Considerations:

  • Same base alloy steel family as BC, but heat treated to a higher strength level.

  • Requires precise heat control to balance high tensile strength with toughness.

  • Manufactured in diameters up to 4 inches.

• Performance in Fasteners:

  • Minimum tensile strength ~150 ksi (higher than BC and B7).

  • Used where maximum strength is required in engineered fasteners.

  • Because of higher hardness, special care is taken to avoid hydrogen embrittlement in surface treatments (like plating).

• Common Uses:

  • Aerospace ground equipment, heavy machinery, power generation systems, and other critical, high-load bolting.