S-91286A260 3/8"-24 x 2 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum load-bearing capacity with Grade 8 classification and 150,000 PSI tensile strength for critical structural applications
• Superior corrosion protection through zinc-flake coating that withstands harsh industrial environments
• Precise thread engagement with Class 2A UNF fine threads ensuring reliable fastening in high-vibration settings
• Optimized torque transmission via external hex drive design that prevents tool slippage during installation
• Enhanced durability from Rockwell C33 hardness rating that maintains fastener integrity under repeated stress
• Versatile partial threading allowing both clamping and alignment functions in assembly operations
• Regulatory compliance meeting ASME B18.2.1, SAE J429 standards plus RoHS 3 and REACH environmental directives

Professional Applications & Engineering Value

These Grade 8 hex head screws deliver exceptional engineering value in heavy machinery, structural steel connections, and high-stress equipment assemblies. The 3/8"-24 UNF fine thread configuration provides superior resistance to vibrational loosening compared to coarse threads, while the zinc-flake coated steel construction offers lasting protection against galvanic corrosion in industrial environments. The partially threaded design creates an optimal balance between clamping force distribution and alignment precision, making these external hex drive fasteners ideal for applications requiring both structural integrity and precise component positioning. With their 150,000 PSI tensile strength and Rockwell C33 hardness, these screws maintain fastener performance in demanding applications where fatigue resistance and reliability are paramount.

Specification Summary & Compliance

Manufactured to exacting Class 2A thread fit tolerances with UNF (Unified National Fine) thread form ensuring consistent engagement across mating components. These 2-3/4" length screws comply with ASME B18.2.1 and SAE J429 Grade 8 specifications for dimensional accuracy and mechanical properties. The fasteners are fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations, making them suitable for global industrial supply chains with stringent environmental requirements.