S-91268A125 1 1/8"-7 x 6 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With 150,000 psi tensile strength, this screw provides superior load-bearing capacity and reliability in high-stress applications.
• High-Strength Grade 8 Material – Made from Grade 8 steel with Rockwell C33 hardness, ensuring excellent durability and resistance to wear and deformation.
• Coarse UNC Thread Design – The 1 1/8"-7 UNC coarse thread offers faster installation and better performance in materials prone to vibration or debris.
• Class 2A Thread Fit – Delivers consistent, reliable engagement with standard nuts and tapped holes, reducing assembly time and improving joint integrity.
• Partially Threaded Shank – Provides enhanced clamping force and shear resistance, ideal for applications requiring precise unthreaded grip length.
• External Hex Drive – Allows for high-torque installation with common tools, ensuring secure fastening in demanding industrial environments.
• Compliance with Industry Standards – Meets ASME B18.2.1 and SAE J429 specifications, guaranteeing dimensional accuracy and performance consistency.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in heavy machinery, structural assemblies, and industrial equipment where high tensile strength and vibration resistance are paramount. The 1 1/8"-7 UNC coarse thread ensures reliable fastening in softer materials or environments subject to movement, reducing the risk of loosening. Its partially threaded design concentrates clamping force, minimizing stress concentration and improving fatigue life. Made from high-strength steel with Rockwell C33 hardness, it withstands extreme loads and harsh conditions, making it suitable for construction, automotive, and manufacturing sectors. The external hex drive facilitates quick, secure installation, enhancing productivity in maintenance and assembly operations.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances per UNC standards, ensuring compatibility with standard mating components. It conforms to ASME B18.2.1 and SAE J429 specifications for dimensional and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries without hazardous substances.