S-91257A152 7/16"-14 x 5 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 150,000 psi tensile strength and Grade 8 classification for high-stress industrial applications
• Superior corrosion resistance through Zinc Yellow-Chromate plating, extending service life in harsh environments
• Optimized thread engagement with UNC coarse threading and Class 2A fit ensuring reliable installation and vibration resistance
• Enhanced torque transmission via external hex drive design providing secure fastening in heavy-duty assemblies
• Precision manufacturing compliance meeting ASME B18.2.1 and SAE J429 standards for consistent quality and interchangeability
• Partial threading design allowing unthreaded shank sections to function as precision dowels in aligned components
• Rockwell C33 hardness rating delivering exceptional wear resistance and durability under repeated loading cycles

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, these Grade 8 hex head screws solve critical fastening challenges in construction equipment, machinery frames, and structural assemblies. The 7/16"-14 UNC coarse thread configuration prevents cross-threading during installation while maintaining holding power in vibration-prone environments. Zinc Yellow-Chromate plating creates a sacrificial barrier against oxidation, significantly outperforming standard zinc coatings in humid or chemically aggressive settings. The partially threaded design allows the unthreaded shank section to serve as a precision alignment feature in bolted connections, distributing shear loads efficiently. With 150,000 psi tensile strength and Rockwell C33 hardness, these fasteners maintain clamp force under extreme static and dynamic loads, preventing joint failure in critical applications.

Specification Summary & Compliance

Manufactured to exacting dimensional standards with Class 2A thread fit ensuring consistent assembly performance. Complies with ASME B18.2.1 dimensional specifications and SAE J429 mechanical requirements for Grade 8 fasteners. Features right-hand UNC coarse threads with 14 threads per inch and minimum thread length of 1-1/8". The 5-1/4" overall length and external hex drive configuration provide optimal installation accessibility. Meets industry standards for heavy-duty mechanical fastening applications requiring verified material properties and dimensional consistency.