S-94705A831 1 1/4"-8 x 3 1/4" 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 in high-stress applications, reducing the risk of fastener failure.
• ASTM A193 Grade B7 certification guarantees material quality and consistency, meeting rigorous industrial standards for safety and reliability.
• Rockwell C35 hardness provides excellent resistance to wear and deformation, extending service life in demanding environments.
• Class 2A thread fit offers optimal assembly ease while maintaining secure fastening, minimizing installation time and potential cross-threading.
• Fully threaded design allows for maximum grip and adjustability across the entire 3 1/4" length, suitable for various material thicknesses.
• UN fine thread profile delivers superior vibration resistance and clamping force compared to coarse threads, ideal for dynamic load conditions.
• External hex drive with 2" head width enables high-torque installation using standard tools, facilitating quick and secure fastening in confined spaces.

Professional Applications & Engineering Value

This high-strength hex head screw is engineered to address critical challenges in heavy-duty industrial applications such as pressure vessels, structural assemblies, and machinery requiring superior tensile strength and reliability. The ASTM Grade B7 steel construction, combined with Rockwell C35 hardness, ensures exceptional resistance to stress corrosion cracking and thermal creep, making it ideal for elevated temperature services. The UN fine thread (1 1/4"-8) and Class 2A thread fit provide precise engagement and vibration resistance, preventing loosening under dynamic loads. With its fully threaded design and external hex drive, this fastener delivers consistent clamping force and easy installation in demanding environments where failure is not an option.

Specification Summary & Compliance

This hex head screw features a 1 1/4"-8 UN fine thread with Class 2A thread fit per ASME B1.1 standards, ensuring precise dimensional accuracy and interchangeability. Manufactured in compliance with ASTM A193 Grade B7 specifications, it meets requirements for high-temperature service and pressure-containing applications. The fastener maintains a right-hand thread direction, 3 1/4" length, and 2" head width with 25/32" head height for consistent performance. While specific RoHS/REACH compliance should be verified per batch, the steel material and manufacturing process typically adhere to industrial environmental and safety standards for industrial fasteners.