S-91286A371 1/2"-20 x 1 3/4" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength: With a 150,000 psi tensile strength and Rockwell C33 hardness, this screw provides reliable performance under extreme loads, reducing the risk of failure in demanding applications.
• Superior Corrosion Resistance: The zinc-flake coating offers excellent protection against rust and environmental factors, extending the service life of your assemblies in harsh industrial settings.
• Precision Threading for Secure Fastening: Fully threaded with 1/2"-20 UNF fine threads and Class 2A fit, ensuring tight, vibration-resistant connections and easy installation in precision-machined components.
• High-Grade Material Durability: Made from Grade 8 steel, this hex head screw withstands high stress and repetitive use, ideal for heavy-duty machinery and structural applications.
• Optimized Drive Efficiency: The external hex drive and 3/4" head width allow for high torque application with standard tools, speeding up assembly and disassembly processes.
• Compliance with Industry Standards: Meets ASME B18.2.1 and SAE J429 specifications, ensuring consistency, reliability, and interchangeability in professional engineering projects.
• Environmental and Safety Assurance: RoHS 3 and REACH compliant, providing peace of mind for use in regulated industries without harmful substances.

Professional Applications & Engineering Value

This Grade 8 hex head screw is engineered to address critical challenges in industrial environments, such as vibration loosening and corrosion-induced failures. The zinc-flake coated steel construction delivers robust corrosion resistance, making it suitable for outdoor equipment, automotive assemblies, and heavy machinery exposed to moisture and chemicals. With fully threaded 1/2"-20 UNF fine threads and a Class 2A fit, it ensures precise alignment and secure fastening in high-stress applications, reducing maintenance downtime. The external hex drive facilitates quick installation with common tools, enhancing workflow efficiency in manufacturing and construction sectors where reliability and speed are paramount.

Specification Summary & Compliance

This fastener features a 1/2"-20 UNF thread with Class 2A tolerance for accurate fit, and is fully threaded with right-hand direction. It complies with ASME B18.2.1 and SAE J429 standards, ensuring consistent quality and performance. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in various industrial applications without environmental hazards.