ASTM A193 B8 Bolts

ASTM A193 B8 fasteners are a kind of high-performing bolting products made from austenitic stainless steel — Grade 304 (UNS S30400) — primarily for use in applications where standard carbon or alloy steels could not be used due to corrosion or oxidation. The “B8” designation is synonymous with excellent corrosion resistance to atmospheric corrosion, to a wide variety of organic/inorganic chemicals, and to high temperatures. 

The ASTM A193 standard specifically governs the chemical composition of ASME SA193 B8 material such that no unknown elements can be added during manufacturing. This guarantees consistent, predictable performance and superior corrosion resistance across every batch. This reliability makes products like the A193 B8 threaded rod and washer ideal for stabilizing structures in construction, securing equipment in chemical plants, or any application where long-term integrity is paramount.

The ASTM A193 B8 specification has two classes of performance (Class 1 and Class 2), which relate to performance based on manufacturing process and resultant mechanical properties. Choosing the correct class is critical for application safety and performance.

A193 B8 Class 1 fasteners are carbide solution treated (also called solution annealed) to guarantee a fully solution treated microstructure. The heat treatment for Class 1 fasteners dissolves any chromium carbides that may have developed in the manufacturing process and allows for maximum corrosion resistance and ductility. B8 Class 1 bolts have a minimum tensile strength of 75 ksi, are the standard for general applications with corrosion resistance being favored to high strength.

A193 B8 Class 2 fasteners undergo an additional step, they are strain-hardened (also called cold worked) after the initial solution treatment. The strain-hardening process introduces a significant amount of hardness and strength to the material while still maintaining reputable corrosion resistance. As a result, Class 2 bolts have a much higher minimum tensile strength of 125 ksi and are generally reserved for heavy bolting applications, high strength pipeline bolting and structural components with considerations for both strength and environmental factors.

Our ASTM A193 B8 fasteners are manufactured in compliance with a range of international dimensional standards, ensuring interchangeability and proper fitment for global projects. Below are some of the most common standards we adhere to.

“Contact Jade Special Metals today with your requirement for ASTM A193 B8 Bolts. We assure you of the best quote.

The exceptional corrosion resistance of ASTM A193 Gr B8 makes it ideal for:

Chemical Processing: Resists corrosion from a wide range of chemicals.
Food & Beverage Industry: Hygienic and easy to clean, preventing contamination.
Marine & Coastal Environments: Withstands saltwater and humid conditions.
Water Treatment & Plumbing: Excellent performance in water and wastewater systems.
Pharmaceutical & Medical Equipment: Where cleanliness and corrosion resistance are paramount.
Pulp & Paper Industry: Resists corrosive compounds used in paper production.

• Manufacturing Experts: As a direct manufacturer and exporter, we control the entire manufacturing process and ensure you benefit from a competitive price.
• Certified Quality: All of our A193 B8 fasteners come with Mill Test Certificates (MTC) to EN 10204 3.1, with complete traceability and compliance.
• Bulk Inventory: We have a lot of inventory in the A193 B8 Bolts in Class 1 and Class 2, so we can dispatch immediately.
• Custom Sizes and Speciality Fasteners: We are specialists in the custom manufacture of different sizes, lengths and unique fasteners specifically manufactured to your specifications.
• Technical Support: Our knowledgeable support team can assist you in choosing the correct grade and class for your requirements.