S-91268A166 1/4"-20 x 5 1/2" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 150,000 psi ensures reliable performance in demanding industrial applications
• Grade 8 steel construction with Rockwell C33 hardness provides superior durability and resistance to wear
• Partial UNC coarse threading with Class 2A fit offers optimal engagement while reducing installation time
• External hex drive design enables secure tool engagement and high torque application capabilities
• Heavy-duty 5½" length with ¾" minimum thread length accommodates thick material assemblies
• Comprehensive compliance with ASME B18.2.1 and SAE J429 standards guarantees engineering precision
• Environmental responsibility through RoHS 3 and REACH compliance for sustainable operations

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver critical engineering solutions for heavy machinery, structural frameworks, and industrial equipment where failure is not an option. The 150,000 psi tensile strength and Rockwell C33 hardness provide exceptional resistance to vibration loosening and mechanical stress, while the UNC coarse thread pattern ensures rapid installation in thick materials. The partial threading design concentrates strength where needed most, making these steel fasteners ideal for applications requiring both clamping force and shear resistance. The external hex drive accommodates standard tools for maintenance accessibility in confined industrial environments.

Specification Summary & Compliance

This 1/4"-20 x 5½" hex head screw features Class 2A thread fit per UNC standards with precise dimensional accuracy. Manufacturing complies with ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring consistent quality and performance. The product meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, making it suitable for regulated industrial applications worldwide.