S-91247A729 1/2"-13 x 3 3/4" ASME B18.2.1, SAE J429 Medium-Strength Grade 5 Steel Hex Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength (120,000 psi) provides reliable performance in demanding applications, reducing the risk of fastener failure
• Zinc plating finish offers superior corrosion resistance, extending service life in various environmental conditions
• Grade 5 classification ensures consistent mechanical properties and durability for industrial applications
• Coarse UNC threads with Class 2A fit enable faster assembly and better vibration resistance compared to fine threads
• External hex drive design allows for high torque application with standard tools, improving installation efficiency
• Partially threaded shank provides unthreaded bearing surface for improved shear strength in structural connections
• Rockwell C25 hardness maintains thread integrity and prevents stripping during repeated installations

Professional Applications & Engineering Value

These Grade 5 hex head screws deliver critical engineering value through their optimized material composition and coarse UNC thread design. The zinc plated steel construction addresses common industrial challenges by providing essential corrosion protection in environments where moisture or chemical exposure could compromise fastener integrity. The partially threaded configuration offers distinct advantages in structural applications where the unthreaded portion provides enhanced shear resistance, making these external hex drive fasteners ideal for heavy machinery, construction frameworks, and equipment assembly. With their 1/2"-13 thread size and substantial 3 3/4" length, they solve connection challenges in thick materials while the Class 2A thread fit ensures consistent engagement without binding, streamlining installation processes in production environments.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit tolerances and UNC coarse threading manufactured to exacting standards. The fastener complies with ASME B18.2.1 and SAE J429 Grade 5 specifications, ensuring dimensional accuracy and mechanical performance. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) requirements, confirming the product meets current regulatory standards for hazardous substance restrictions.