S-91257A663 3/8"-24 x 3" 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 for reliable performance in demanding applications
• Superior corrosion resistance provided by zinc yellow-chromate plating for extended service life in harsh environments
• Precise thread engagement with Class 2A UNF fine threads ensuring secure fastening and vibration resistance
• Optimized strength-to-weight ratio through Grade 8 steel construction with Rockwell C33 hardness
• Easy installation and removal with external hex drive design and standard 9/16" head width
• Versatile partial threading allowing for both clamping and alignment functions in assembly operations
• Regulatory compliance assurance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance in critical assemblies where failure is not an option. The combination of 150,000 PSI tensile strength and Rockwell C33 hardness ensures reliable operation under extreme mechanical stress, while the zinc yellow-chromate plating provides superior protection against corrosion in challenging environments. The 3/8"-24 UNF fine thread configuration offers enhanced vibration resistance compared to coarse threads, making these partially threaded screws ideal for machinery, structural steel connections, and heavy equipment where precise clamping force and alignment are essential. The external hex drive design facilitates efficient installation with standard tools, reducing assembly time in manufacturing and maintenance operations.

Specification Summary & Compliance

This 3/8"-24 x 3" hex head screw features Class 2A thread fit tolerance for precise engagement and meets ASME B18.2.1 and SAE J429 specifications for dimensional accuracy and mechanical properties. The fastener is manufactured in the inch system with a minimum thread length of 1" and partial threading design. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental responsibility and workplace safety standards are maintained throughout the product lifecycle.