S-91286A402 5/8"-11 x 2 1/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum load-bearing capability with Grade 8 classification and 150,000 psi tensile strength for critical structural applications
• Superior corrosion resistance through zinc-flake coating that withstands harsh industrial environments
• Optimized thread engagement with UNC coarse threading and Class 2A fit ensuring reliable installation and vibration resistance
• Enhanced installation efficiency featuring external hex drive design for high-torque applications and easy wrench access
• Exceptional material durability from Rockwell C33 hardened steel that maintains integrity under extreme stress conditions
• Versatile partial threading allowing for both clamping force and precise positioning in assembled components
• Full regulatory compliance meeting ASME B18.2.1, SAE J429, RoHS 3, and REACH standards for global industrial use

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance where failure is not an option. The zinc-flake coated steel construction provides superior corrosion protection in demanding environments, while the 5/8"-11 UNC coarse threading ensures rapid assembly and reliable grip in structural steel, heavy machinery, and construction equipment. The external hex drive design accommodates high torque requirements, making these partially threaded screws ideal for applications requiring both clamping force and precise component alignment. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners maintain integrity under extreme vibrational loads and shock conditions common in mining, transportation, and industrial manufacturing sectors.

Specification Summary & Compliance

This 5/8"-11 hex head screw features precise Class 2A thread fit with UNC coarse threading and 2 1/4" length manufactured to exacting standards. The fastener meets ASME B18.2.1 and SAE J429 Grade 8 specifications, ensuring dimensional accuracy and mechanical properties. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, these screws are suitable for global industrial applications requiring environmental and safety compliance while maintaining 150,000 psi tensile strength and Rockwell C33 hardness throughout their service life.