S-91251A734 1/2"-13 x 5 1/2" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi provides superior resistance to breaking and stripping under high-stress conditions
• Premium black-oxide coating on alloy steel offers enhanced corrosion resistance for extended service life in demanding environments
• Class 3A thread fit ensures precise, secure mating with nuts and tapped holes, minimizing vibration-induced loosening
• Partially threaded design with 1½" minimum thread length allows for optimal clamp force distribution and easier alignment
• Hex socket drive with 3/8" drive size enables high-torque installation in confined spaces without slippage
• UNC coarse threading provides faster assembly and reduced cross-threading risk compared to fine thread alternatives
• Rockwell C37 hardness maintains thread integrity and drive socket geometry through repeated installation cycles

Professional Applications & Engineering Value

Engineered for high-performance industrial applications, these black-oxide alloy steel socket head cap screws solve critical fastening challenges where vibration resistance and reliability are paramount. The UNC coarse thread configuration combined with Class 3A precision ensures consistent clamping force in heavy machinery, automotive assemblies, and structural frameworks. The partially threaded design concentrates stress away from the shank, preventing fatigue failure in dynamic loading scenarios. The hex socket drive accommodates high installation torque without damaging the fastener head, making them ideal for maintenance-critical equipment where repeated disassembly is required. These socket head cap screws deliver predictable performance in applications demanding both mechanical strength and chemical resistance.

Specification Summary & Compliance

This 1/2"-13 UNC socket head cap screw features Class 3A thread fit for precision assembly, with a minimum thread length of 1½" on a 5½" overall length. Manufactured to ASTM A574 specification for alloy steel socket head cap screws, ensuring consistent mechanical properties and dimensional accuracy. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, making them suitable for global industrial applications with strict material restrictions.