S-91247A646 3/8"-16 x 5 1/2" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 120,000 psi ensures reliable performance in demanding applications, reducing the risk of fastener failure under heavy loads.
• Zinc plating provides superior corrosion resistance, extending the service life of the screw in harsh or outdoor industrial environments.
• Grade 5 classification and Rockwell C25 hardness offer a robust balance of strength and durability, suitable for high-stress assemblies.
• Coarse UNC threading and Class 2A thread fit enable quick, secure installation and easier alignment, minimizing assembly time and errors.
• External hex drive and hex head design allow for high-torque application with standard tools, ensuring tight fastening in confined spaces.
• Partial threading provides unthreaded shank strength where needed, ideal for applications requiring clamping force without full-length threads.
• Compliance with ASME, SAE, RoHS, and REACH standards guarantees quality, safety, and environmental responsibility for global industrial use.

Professional Applications & Engineering Value

This Grade 5 hex head screw is engineered to address critical fastening challenges in industrial settings, such as machinery assembly, structural frameworks, and heavy equipment maintenance. The zinc plated steel construction combats corrosion, prolonging lifespan in humid or chemically exposed environments. With 3/8"-16 UNC coarse threading and Class 2A thread fit, it ensures precise engagement and vibration resistance, reducing loosening in dynamic applications. The external hex drive facilitates efficient installation with common wrenches, while the partial threading design optimizes grip strength in jointed materials. Ideal for construction, automotive, and manufacturing sectors, this screw delivers consistent performance where reliability and compliance with ASME B18.2.1 and SAE J429 standards are paramount.

Specification Summary & Compliance

This screw adheres to precise dimensional standards, including Class 2A thread fit for consistent accuracy and UNC coarse thread specifications. It meets ASME B18.2.1 and SAE J429 manufacturing guidelines, ensuring interoperability and safety. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it supports environmental and health standards without compromising on the 120,000 psi tensile strength and Rockwell C25 hardness.