S-92620A129 1/2"-28 x 2 1/2" 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 high-stress applications
• Superior corrosion resistance provided by zinc yellow-chromate plating, extending service life in demanding environments
• Precise thread engagement with UNEF extra fine thread spacing and Class 2A fit for secure fastening in thin materials
• Optimized torque transmission through the external hex drive and 3/4" head width for efficient installation
• Enhanced durability with Rockwell C33 hardness rating, maintaining structural integrity under repeated stress
• Versatile partial threading design allowing for both clamping and alignment functions in assembly applications
• Industry-standard compliance with ASME B18.2.1 and SAE J429 specifications ensuring consistent quality and interchangeability

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical performance advantages in demanding industrial settings where failure is not an option. The combination of 150,000 psi tensile strength and Rockwell C33 hardness provides exceptional resistance to vibration loosening and fatigue failure in heavy machinery, structural steel connections, and high-pressure equipment. The 1/2"-28 UNEF extra fine thread configuration offers superior holding power in thin-section materials and precision components where standard threads would compromise integrity. The zinc yellow-chromate plating creates a robust barrier against corrosion in outdoor applications or environments exposed to moisture and chemicals. With partial threading and external hex drive design, these fasteners enable precise clamping force control while facilitating quick installation and removal with standard tools.

Specification Summary & Compliance

This Grade 8 hex head screw features precise Class 2A thread fit tolerances with 1/2"-28 UNEF extra fine thread spacing and right-hand thread direction. The fastener maintains dimensional compliance with ASME B18.2.1 and material specifications per SAE J429 standards. Manufacturing follows rigorous quality controls to ensure consistent 2 1/2" length, 5/16" head height, and 3/4" head width dimensions. The zinc yellow-chromate plating meets industry requirements for corrosion protection while maintaining compatibility with various industrial applications.