S-91286A249 3/8"-24 x 1 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength: Withstands up to 150,000 psi, providing reliable performance in high-stress industrial applications.
• Superior Corrosion Resistance: Zinc-flake coating offers excellent protection against rust and environmental degradation, extending service life.
• High-Grade Material Hardness: Rockwell C33 hardness ensures durability and resistance to wear and deformation under heavy loads.
• Precision Thread Fit: Class 2A thread fit with UNF fine threading ensures secure, vibration-resistant fastening in critical assemblies.
• Optimized Drive Design: External hex head allows for high-torque installation and easy removal with standard tools, reducing assembly time.
• Partial Threading for Versatility: Combines threaded and unthreaded sections for improved grip and alignment in varied material thicknesses.
• Compliance with Industry Standards: Meets ASME B18.2.1 and SAE J429 specifications, ensuring interoperability and reliability in engineered systems.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address common industrial challenges such as joint failure under dynamic loads and corrosion in harsh environments. The zinc-flake coated steel construction provides a robust barrier against moisture and chemicals, making it ideal for automotive, machinery, and structural applications where long-term reliability is critical. The 3/8"-24 UNF fine thread and Class 2A fit ensure precise engagement, reducing the risk of loosening due to vibration. With partial threading, it offers flexibility in clamping different material thicknesses, while the external hex drive facilitates efficient installation in confined spaces. These features collectively enhance assembly integrity, minimize maintenance needs, and support compliance with rigorous industrial standards.

Specification Summary & Compliance

This fastener adheres to Class 2A thread fit tolerances per UNF standards, ensuring dimensional accuracy and compatibility. It conforms to ASME B18.2.1 and SAE J429 specifications for hex head screws and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental safety and material restrictions are met.