S-91274A504 1/2"-13 x 5 1/2" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the zinc-flake coating extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit guarantees secure, vibration-resistant assemblies with consistent clamping force.
• High hardness (Rockwell C37) provides excellent wear resistance, maintaining dimensional stability under heavy loads.
• 3/8" hex drive design allows for easy installation and removal with standard tools, improving assembly efficiency.
• Partially threaded shank offers optimal grip length control, preventing thread damage in blind holes.
• Compliance with major standards including ASME B18.3 ensures interchangeability and quality consistency across industrial applications.

Professional Applications & Engineering Value

This zinc-flake-coated alloy steel socket head cap screw addresses critical engineering challenges in demanding environments. The 1/2"-13 UNC coarse thread with Class 3A fit provides superior resistance to loosening under vibration, making it ideal for heavy machinery, automotive assemblies, and structural frameworks. The zinc-flake coating delivers exceptional corrosion protection that surpasses conventional platings, significantly reducing downtime in corrosive industrial settings. With its 170,000 psi tensile strength and Rockwell C37 hardness, this fastener maintains integrity in high-load applications where standard fasteners would deform or fail. The partially threaded design allows for precise clamping force distribution while the 3/8" hex drive ensures quick installation in confined spaces, streamlining maintenance and assembly processes across manufacturing, construction, and equipment maintenance sectors.

Specification Summary & Compliance

This socket head cap screw features precision 1/2"-13 UNC coarse threads with Class 3A thread fit for optimal engagement and vibration resistance. The product strictly adheres to ASME B18.3 dimensional specifications and is manufactured from ASTM A574 alloy steel. Corrosion resistance is validated through ASTM B117 testing protocols. The fastener is fully compliant with RoHS 3 (2015/863/EU) restrictions on hazardous substances and meets REACH (EC 1907/2006) requirements for chemical safety, ensuring environmental responsibility and workplace safety.