S-91257A977 1"-8 x 8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength, ideal for high-stress industrial applications.
• Superior corrosion resistance from zinc yellow-chromate plating, extending service life in harsh environments.
• High hardness rating of Rockwell C33 ensures minimal wear and deformation under heavy use.
• Reliable coarse UNC threading provides faster assembly and reduced cross-threading risks.
• Precise Class 2A thread fit guarantees consistent engagement and vibration resistance.
• Partially threaded design allows for optimal clamping force distribution in structural joints.
• Compliance with ASME B18.2.1 and SAE J429 ensures interchangeability and performance reliability.

Professional Applications & Engineering Value

Engineered for demanding industrial environments, this Grade 8 hex head screw combines high-strength steel material with a zinc yellow-chromate finish to resist corrosion in outdoor or chemical-exposed settings. The 1"-8 UNC coarse thread and external hex drive facilitate quick installation in heavy machinery, construction frameworks, and transportation equipment, where vibration loosening is a concern. Its partially threaded shank concentrates clamping force precisely, preventing joint failure in high-load assemblies. By meeting rigorous standards, it delivers consistent performance in structural fastening and mechanical systems, reducing maintenance downtime and ensuring operational safety.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit per UNC standards, ensuring dimensional accuracy. It complies with ASME B18.2.1 and SAE J429 specifications for Grade 8 bolts, and is verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, supporting environmental and safety regulations.