S-91257A688 7/16"-14 x 4 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Maximum Load Capacity - Grade 8 classification with 150,000 psi tensile strength ensures superior performance in high-stress industrial applications
• Enhanced Corrosion Protection - Zinc yellow-chromate plating provides excellent resistance against rust and environmental degradation
• Secure Installation & Removal - External hex drive design allows for high torque application and reliable fastening control
• Optimized Thread Engagement - Class 2A thread fit with UNC coarse threading ensures proper seating and vibration resistance
• Partial Threading Efficiency - 1 1/8" minimum thread length provides focused engagement where needed while reducing material usage
• Heavy-Duty Material Integrity - Steel construction with Rockwell C33 hardness maintains structural stability under extreme conditions
• Industry Standard Compliance - Meets ASME B18.2.1 and SAE J429 specifications for guaranteed quality and interchangeability

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these Grade 8 hex head screws deliver exceptional performance where failure is not an option. The 7/16"-14 UNC coarse thread configuration provides superior holding power in structural steel applications, construction equipment, and heavy machinery assemblies. The zinc yellow-chromate plating offers critical corrosion protection in outdoor or chemically aggressive settings, significantly extending service life. With partial threading and 4 3/4" length, these fasteners optimize material strength distribution while providing ample unthreaded shank for shear load applications. The external hex drive ensures reliable installation even in confined spaces, making them ideal for maintenance, repair, and OEM applications where access may be limited.

Specification Summary & Compliance

This heavy-duty hex head screw features precise Class 2A thread fit tolerance per UNC standards, ensuring proper engagement and interchangeability. Manufactured to comply with ASME B18.2.1 and SAE J429 Grade 8 specifications, the fastener delivers consistent dimensional accuracy and mechanical properties. The coarse thread spacing (14 TPI) provides optimal performance in structural steel and aluminum applications. With Rockwell C33 hardness and 150,000 psi tensile strength, this industrial-grade fastener meets the rigorous demands of construction, manufacturing, and heavy equipment industries while maintaining compliance with industry-standard manufacturing protocols.