S-94705A821 1 1/8"-8 x 5 1/2" 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 industrial applications, reducing the risk of fastener failure.
• High hardness rating of Rockwell C35 provides superior resistance to wear and deformation, extending service life in demanding environments.
• Partially threaded design with 3" grip length offers optimal clamping force distribution and prevents loosening under vibration.
• Class 2A thread fit and UN fine threads deliver precise, secure engagement and improved fatigue resistance compared to coarse threads.
• External hex drive and 1 13/16" head width allow for easy installation and high torque application with standard tools.
• Manufactured from ASTM A193 Grade B7 steel guarantees consistent material quality and performance in high-temperature and high-pressure applications.
• 5 1/2" overall length provides versatility for a wide range of thick assembly requirements.

Professional Applications & Engineering Value

This high-strength hex head screw is engineered to address critical challenges in heavy machinery, pressure vessels, and structural assemblies where failure is not an option. The ASTM Grade B7 steel construction, combined with a partially threaded design and fine UN thread spacing, ensures maximum clamp load retention and vibration resistance. The external hex drive facilitates quick installation even in confined spaces, while the Rockwell C35 hardness and 125,000 PSI tensile strength provide durability against dynamic loads and thermal cycling. Ideal for industrial fasteners in oil & gas, power generation, and construction, it delivers long-term reliability under extreme mechanical stress and environmental conditions.

Specification Summary & Compliance

This screw features a 1 1/8"-8 UN fine thread with Class 2A thread fit for precise dimensional accuracy. It complies with ASTM A193 specifications for high-temperature service and is manufactured from ASTM Grade B7 steel. The product meets industry standards for mechanical properties, including tensile strength and hardness, ensuring consistent performance in critical applications. It is supplied as an inch fastener with a total length of 5 1/2", thread length of 2 1/2", and grip length of 3", designed for reliable operation in regulated industrial environments.