S-94705A798 1 1/8"-8 x 2 3/4" ASTM A193 Steel Heavy Hex Head Screws for High-Pressure Applications

Key Features & Benefits at a Glance

• Exceptional tensile strength of 125,000 PSI ensures reliable performance under extreme loads, reducing the risk of fastener failure in critical applications.
• High hardness rating (Rockwell C35) provides superior resistance to wear and deformation, extending service life in abrasive environments.
• Fully threaded design offers consistent clamping force along the entire length, improving joint stability and vibration resistance.
• Class 2A thread fit with UN fine threads delivers precise engagement and easier assembly while maintaining high fatigue strength.
• External hex drive allows for high-torque installation using standard tools, ensuring secure fastening in confined spaces.
• ASTM A193 Grade B7 steel construction guarantees material integrity and compliance with industry standards for high-temperature and high-pressure services.
• Robust dimensions (1 13/16" head width, 2 3/4" length) provide ample bearing surface and grip range for heavy-duty structural connections.

Professional Applications & Engineering Value

This 1 1/8"-8 hex head screw is engineered to address demanding industrial challenges where fastener reliability is non-negotiable. Manufactured from ASTM Grade B7 steel, it maintains mechanical properties under elevated temperatures, making it ideal for pressure vessels, valve assemblies, and structural supports in petrochemical and power generation sectors. The fully threaded, right-hand UN fine thread design ensures uniform stress distribution and superior resistance to loosening under dynamic loads. With its external hex drive and Class 2A thread fit, installation is streamlined while achieving consistent preload—critical for flanged connections and heavy machinery where safety and durability are paramount. This screw’s combination of 125,000 PSI tensile strength and Rockwell C35 hardness provides a dependable solution for high-stress applications, reducing maintenance downtime and enhancing operational safety.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances per UN standards, ensuring precise dimensional accuracy and interchangeability. It conforms to ASTM A193 specifications for high-temperature bolting materials, with full traceability to material and manufacturing requirements. The screw meets industry standards for heavy-duty industrial use, including compliance with relevant RoHS and REACH directives for environmental safety. Threading follows UN fine thread (1 1/8"-8) specifications, providing optimal performance in applications requiring fine adjustment and high fatigue resistance.