S-91274A268 5/16"-18 x 2 1/2" 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, ideal for harsh industrial environments and extending service life.
• Superior high-strength performance with 170,000 psi tensile strength and Rockwell C37 hardness for reliable load-bearing in critical assemblies.
• Precise and secure fastening ensured by Class 3A thread fit, minimizing the risk of loosening under vibration and stress.
• Optimized for high-torque applications featuring a standard socket head and 1/4" hex drive for easy installation and removal with common tools.
• Versatile partial threading allows for a non-threaded shank section, providing enhanced shear strength and precise clamp-up in designated applications.
• Broad industry compliance meeting ASME B18.3 and ASTM A574 standards, ensuring consistent quality and interchangeability.
• Environmentally responsible manufacturing with RoHS 3 and REACH compliance, supporting your green procurement initiatives.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, this Socket Head Cap Screw is constructed from zinc-flake-coated alloy steel, providing a robust barrier against corrosion and chemical exposure, which is critical in manufacturing, automotive, and heavy machinery. The UNC coarse threads and Class 3A thread fit deliver superior engagement and vibration resistance, reducing maintenance needs in dynamic assemblies. With a partially threaded design, it offers precise clamping force control, preventing thread damage in soft materials and ensuring joint integrity. The combination of high tensile strength and reliable hex drive makes it an ideal choice for high-stress connections where failure is not an option, streamlining assembly processes and enhancing overall equipment durability.

Specification Summary & Compliance

This fastener adheres to strict dimensional and performance standards, including Class 3A thread fit for precise tolerance and UNC coarse thread specifications. It is manufactured in compliance with ASME B18.3 and ASTM A574 standards, ensuring consistent quality and reliability. The product is also verified as RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting current environmental and safety regulations for industrial use.