S-90117A551 1/4"-20 x 2 1/4" ASME B18.3 Alloy Steel Wire-Lockable 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
• Black-oxide coating on alloy steel provides superior corrosion resistance and enhanced durability in demanding industrial environments
• Class 3A thread fit delivers precise, secure mating with nuts and tapped holes, minimizing assembly issues and vibration loosening
• Hex socket drive design allows for high-torque installation in confined spaces, improving assembly efficiency and tool accessibility
• Partially threaded shank offers optimal grip length control, preventing over-tightening and ensuring consistent clamping force
• ASME B18.3 compliance guarantees dimensional accuracy and interchangeability, simplifying procurement and inventory management
• RoHS 3 and REACH compliance ensures environmental responsibility and regulatory adherence for global supply chains

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws with 1/4"-20 UNC coarse threads are engineered to solve critical fastening challenges in heavy machinery, automotive assemblies, and precision equipment. The Class 3A thread fit provides exceptional dimensional stability, eliminating play in high-vibration environments while the partially threaded design concentrates clamping force exactly where needed. The hex socket drive enables flush installation in recessed applications, making them ideal for compact spaces where wrench clearance is limited. With 170,000 psi tensile strength and Rockwell C37 hardness, these screws maintain integrity under extreme loads, preventing stripping and deformation during repeated maintenance cycles.

Specification Summary & Compliance

This socket head cap screw features precise Class 3A thread fit with 1/4"-20 UNC coarse thread spacing in right-hand orientation. Manufacturing conforms to ASME B18.3 specifications ensuring dimensional accuracy across all critical parameters including head diameter (3/8"), drive size (3/16"), and minimum thread length (1"). The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting current substance restriction requirements for industrial applications.