S-91247A550 1/4"-20 x 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 provides reliable performance in high-stress industrial applications
• Superior corrosion resistance through zinc plating extends service life in demanding environments
• Optimized thread engagement with 3/4" minimum thread length ensures secure fastening in various material thicknesses
• Enhanced durability with Rockwell C25 hardness maintains structural integrity under repeated loads
• Industry-standard compatibility with UNC coarse threads and Class 2A fit guarantees proper installation
• Secure external hex drive allows for high-torque installation without stripping or damage
• Comprehensive compliance with major industrial standards ensures quality and reliability

Professional Applications & Engineering Value

These Grade 5 hex head screws deliver exceptional engineering value across multiple industrial sectors. The zinc plated finish provides critical corrosion protection in manufacturing environments, construction sites, and outdoor applications where moisture exposure is common. The 1/4"-20 UNC coarse thread design ensures rapid installation and superior holding power in steel frameworks, machinery assemblies, and structural components. The partially threaded configuration with 2" overall length offers optimal clamping force distribution, making these fasteners ideal for heavy equipment, automotive assemblies, and industrial machinery where vibration resistance and long-term reliability are paramount. The combination of 120,000 psi tensile strength and Rockwell C25 hardness ensures these screws maintain integrity under dynamic loads and extreme conditions.

Specification Summary & Compliance

This hex head screw features precise Class 2A thread fit with 1/4"-20 UNC coarse threads and right-hand thread direction. Manufactured to exacting standards including ASME B18.2.1 and SAE J429 specifications for Grade 5 fasteners. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industries. The inch system measurement provides compatibility with North American industrial standards and equipment.