S-91257A501 1/2"-20 x 10" 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 steel offering 150,000 psi tensile strength for critical structural applications
• Superior corrosion protection through zinc yellow-chromate plating that withstands harsh industrial environments
• Precise thread engagement with UNF fine thread spacing and Class 2A fit ensuring vibration-resistant connections
• Optimized strength-to-weight ratio through Rockwell C33 hardness balancing durability with machinability
• Enhanced installation control with external hex drive and 3/4" head width for secure tool engagement
• Reduced material stress through partial threading design that concentrates strength where needed most
• Industry-standard compliance meeting ASME B18.2.1 and SAE J429 specifications for guaranteed interoperability

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws deliver exceptional performance in construction machinery, structural steel connections, and high-vibration equipment. The UNF fine thread spacing provides superior resistance to loosening under dynamic loads, while the zinc yellow-chromate plating creates a protective barrier against corrosion in outdoor or chemically aggressive environments. The partially threaded design concentrates the 150,000 psi tensile strength precisely at the engagement point, preventing thread stripping and distributing stress efficiently. These 10-inch fasteners with external hex drive are specifically designed for applications requiring both extreme clamping force and reliable, repeated disassembly capabilities.

Specification Summary & Compliance

Manufactured to exact inch system dimensions with Class 2A thread fit tolerance for consistent mating with standard nuts. Complies with ASME B18.2.1 and SAE J429 specifications governing dimensional accuracy, material properties, and performance requirements. The 1/2"-20 UNF thread with right-hand direction and 1 1/2" minimum thread length ensures proper engagement in accordance with industrial standards. Surface treatment meets environmental compliance requirements for industrial use applications.