S-91257A768 9/16"-12 x 2 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 150,000 psi tensile strength and Rockwell C33 hardness for reliable performance in high-stress applications.
• Superior corrosion resistance from Zinc Yellow-Chromate plating, extending service life in harsh industrial environments.
• Secure and efficient fastening with UNC coarse thread spacing and partial threading, reducing installation time and preventing loosening under vibration.
• Precise thread engagement ensured by Class 2A thread fit, providing consistent clamping force and reducing the risk of cross-threading.
• Heavy-duty construction meeting Grade 8 standards, ideal for critical assemblies requiring high mechanical strength and durability.
• Easy installation and removal with external hex drive and 13/16" head width, allowing for standard tool compatibility and high torque application.
• Compliance with major industry standards including ASME B18.2.1 and SAE J429, ensuring quality and interoperability in professional settings.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, this Grade 8 hex head screw combines high-strength steel and Zinc Yellow-Chromate plating to address common challenges like structural fatigue and environmental degradation. The 9/16"-12 UNC coarse thread and partial threading design enhance grip in thick materials, minimizing the risk of shear failure in heavy machinery, construction frameworks, and automotive assemblies. Its 150,000 psi tensile strength and Rockwell C33 hardness ensure long-term reliability under dynamic loads, while the corrosion-resistant finish protects against moisture and chemicals, reducing maintenance costs. Ideal for use in manufacturing, infrastructure, and equipment maintenance, this fastener delivers consistent performance where safety and durability are paramount.

Specification Summary & Compliance

This screw adheres to precise dimensional standards with a Class 2A thread fit and UNC coarse spacing, manufactured in accordance with ASME B18.2.1 and SAE J429 for Grade 8 fasteners. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity.