S-91274A179 1/4"-28 x 3/4" ASME B18.3, ASTM A574, ASTM B117 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-flake coating, extending service life in harsh industrial environments
• Exceptional tensile strength of 170,000 psi ensures reliable performance under high-stress applications
• Precision Class 3A fine threads provide secure, vibration-resistant fastening with minimal play
• Rockwell C37 hardness offers excellent wear resistance and durability for repeated use
• Hex socket drive design allows for high-torque installation in confined spaces
• Full threading along 3/4" length enables adjustable positioning and consistent clamping force
• Compliance with major industry standards including ASME B18.3 and ASTM specifications for guaranteed quality

Professional Applications & Engineering Value

This 1/4"-28 UNF socket head cap screw delivers critical performance advantages for demanding industrial applications. The zinc-flake-coated alloy steel construction provides superior corrosion protection compared to standard coatings, making it ideal for machinery, automotive assemblies, and outdoor equipment exposed to moisture and chemicals. The fine thread configuration (UNF) offers enhanced vibration resistance, preventing loosening in dynamic applications. With Class 3A thread fit precision and 170,000 psi tensile strength, these screws maintain joint integrity under extreme loads while the hex socket drive facilitates secure installation in space-constrained environments where wrench clearance is limited.

Specification Summary & Compliance

Manufactured to exacting Class 3A thread tolerances with UNF fine thread profile (1/4"-28). Complies with ASME B18.3 dimensional specifications, ASTM A574 material requirements, and ASTM B117 salt spray testing standards. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Features right-hand thread direction and fully threaded design for consistent performance.