S-91257A735 1/2"-13 x 5 1/4" 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 harsh environments
• Optimized thread engagement with UNC coarse threading and Class 2A fit ensures secure fastening and vibration resistance
• Heavy-duty construction meeting Grade 8 standards with Rockwell C33 hardness for maximum durability
• Easy installation and removal through external hex drive design with 3/4" head width for standard tool compatibility
• Precision engineering compliance with ASME B18.2.1 and SAE J429 specifications for quality assurance
• Versatile partial threading allows for both clamping and alignment functions in structural applications

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for industrial applications demanding maximum reliability. The 1/2"-13 UNC coarse thread configuration provides superior holding power in structural steel connections, machinery assembly, and heavy equipment manufacturing. The zinc yellow-chromate plating creates a protective barrier against corrosion in outdoor or chemically aggressive environments, significantly reducing maintenance frequency. With partial threading and 5 1/4" length, these fasteners offer optimal unthreaded shank sections for precise alignment while maintaining full tensile strength in threaded regions. The external hex drive design ensures compatibility with standard industrial tools, facilitating efficient installation in confined spaces common in construction, transportation, and manufacturing sectors where ASME B18.2.1 compliance is mandatory.

Specification Summary & Compliance

Manufactured to exacting Class 2A thread fit tolerances with 1/2"-13 UNC coarse thread specifications. These inch system fasteners comply with ASME B18.2.1 dimensional standards and SAE J429 material requirements for Grade 8 fasteners. The zinc yellow-chromate plating meets industry corrosion protection standards while maintaining dimensional accuracy. Product manufacturing adheres to quality systems ensuring consistent Rockwell C33 hardness and 150,000 psi tensile strength performance across production batches.