ASTM Steel

ASTM A193 B7 & A320 L7 Stockholder – High-Performance Bolting Steel

At Midland Bright Steels, we are a leading stockholder of ASTM A193 B7 and ASTM A320 L7, two high-performance bolting specifications designed for medium to high-temperature and low-temperature applications, respectively. These steels are widely used in the petrochemical, oil & gas, and power generation industries, where strength, durability, and resistance to extreme conditions are essential.

ASTM A193 B7 – Medium to High-Temperature Bolting Steel

ASTM A193 B7 is a heat-treated Chromium Molybdenum steel, specifically engineered for bolting applications at temperatures up to 450°C (840°F). This grade offers excellent tensile strength, toughness, and corrosion resistance, making it a preferred choice for high-stress environments.

ASTM A320 L7 – Low-Temperature Bolting Steel

ASTM A320 L7 shares the same chemical and mechanical properties as B7 but is designed for low-temperature applications. This grade undergoes additional Charpy V Notch testing at -101°C (-150°F) to ensure reliable performance in sub-zero conditions, making it ideal for cryogenic and arctic environments.

Manufacturing Process & Quality Assurance

Both B7 and L7 steels are manufactured using Electric Arc Furnace (EAF) technology, continuously cast, followed by heat treatment and Bright conversion for enhanced surface quality. This process ensures high purity, strength, and consistency, meeting strict ASTM standards.

Applications of B7 & L7 Steel

These bolting steels are primarily used for the manufacture of:

• Bolts – Critical for securing structural and mechanical components.
• Fasteners – Used in high-pressure and high-temperature applications.
• Studs & Studbolts – Essential for assembling flanges, pressure vessels, and pipework in the petrochemical industry.

Stock Availability & Size Range

We stock ASTM A193 B7 & A320 L7 in a variety of forms, available Drawn or Turned, depending on size:

• Metric & Imperial sizes – Standard and Thread Rolling Diameters available.
• Typical stock range:
  • B7/L7: 8mm to 4” Diameter
  • B7 only: 110mm to 130mm Diameter

Your Trusted Bolting Steel Supplier

With our extensive stock levels and expertise, Midland Bright Steels ensures fast delivery, competitive pricing, and expert advice for all your B7 and L7 steel requirements.

Contact Us Today

For more information or to place an order, contact Midland Bright Steels today. Our team is ready to assist you with the right bolting steel solutions for your applications.