S-91274A440 1/2"-13 x 7/8" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with zinc-flake coating, ensuring long-term reliability in harsh industrial environments
• Superior tensile strength of 170,000 PSI for heavy-duty applications requiring maximum load-bearing capacity
• Precision Class 3A thread fit providing secure, vibration-resistant connections with minimal risk of loosening
• High hardness rating of Rockwell C37 for excellent wear resistance and durability under repeated stress
• 3/8" hex drive compatibility with standard tools for easy installation and maintenance in confined spaces
• Full compliance with ASME B18.3 and ASTM standards ensuring consistent quality and interchangeability
• RoHS 3 and REACH environmental compliance meeting global regulatory requirements for sustainable manufacturing

Professional Applications & Engineering Value

These zinc-flake-coated alloy steel socket head cap screws deliver critical performance advantages in demanding industrial applications. The combination of 170,000 PSI tensile strength and Rockwell C37 hardness makes them ideal for heavy machinery, automotive assemblies, and construction equipment where vibration resistance and structural integrity are paramount. The Class 3A thread fit with UNC coarse threads ensures rapid assembly and disassembly while maintaining secure fastening under dynamic loads. The zinc-flake coating provides superior corrosion protection compared to conventional platings, significantly extending service life in outdoor or chemically aggressive environments. These socket head cap screws solve common engineering challenges by offering reliable fastening solutions that withstand extreme operating conditions while simplifying maintenance procedures.

Specification Summary & Compliance

This 1/2"-13 UNC socket head cap screw features precision Class 3A thread fit with coarse thread spacing for optimal engagement. Manufactured to ASME B18.3 dimensional specifications and ASTM A574 material standards, ensuring consistent quality and performance. The product fully complies with ASTM B117 salt spray testing requirements, RoHS 3 (2015/863/EU) restrictions on hazardous substances, and REACH (EC 1907/2006) regulations for chemical safety. All dimensions conform to inch system measurements with 3/8" hex drive and 7/8" length specifications.