S-91286A512 3/4"-16 x 3 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-flake coating, extending service life in harsh industrial environments
• Precise thread engagement with Class 2A fit and UNF fine threads ensuring secure, vibration-resistant connections
• Optimal hardness balance at Rockwell C33 for excellent durability without compromising machinability
• Enhanced torque transmission through the external hex drive design, allowing for efficient installation with standard tools
• Partial threading design providing both gripping strength and clearance where needed for versatile applications
• Industry-standard compliance meeting ASME B18.2.1 and SAE J429 specifications for guaranteed quality and interchangeability

Professional Applications & Engineering Value

This Grade 8 steel hex head screw delivers exceptional engineering value for demanding industrial applications where failure is not an option. The combination of 150,000 psi tensile strength and Rockwell C33 hardness provides the perfect balance between durability and fatigue resistance, making it ideal for heavy machinery, structural assemblies, and equipment subjected to dynamic loads. The zinc-flake coating offers superior protection against corrosion in challenging environments, while the UNF fine threads and Class 2A fit ensure precise, vibration-resistant connections that maintain integrity under stress. The partially threaded design allows for both clamping force and clearance, making these hex head screws versatile solutions for construction, manufacturing, and maintenance applications requiring reliable, high-strength fastening.

Specification Summary & Compliance

This heavy-duty fastener features precision 3/4"-16 UNF fine threads with Class 2A thread fit for consistent engagement and reliable performance. Manufactured to exacting standards including ASME B18.2.1 and SAE J429 specifications, ensuring dimensional accuracy and mechanical properties. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making it suitable for global industrial applications requiring both performance and regulatory adherence.