S-91205A667 1/4"-28 x 1 1/4" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Reliable vibration resistance with a nylon patch thread locker that maintains integrity from -70°F to 250°F, reducing loosening in dynamic environments.
• Exceptional tensile strength of 170,000 psi ensures secure fastening under high-stress conditions, minimizing failure risks.
• Precise Class 3A thread fit provides tighter tolerances for smoother assembly and improved load distribution in fine-thread applications.
• Durable black-oxide finish on alloy steel offers corrosion resistance and a professional appearance for long-term use.
• Hex socket drive design allows for high-torque installation with standard tools, enhancing efficiency in confined spaces.
• Full threading along the 1 1/4" length enables adjustable positioning and uniform clamping force across joints.
• Compliance with industry standards like ASME B18.3 and ASTM A574 guarantees consistent quality and interoperability in mechanical systems.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address common industrial challenges such as vibration-induced loosening and thermal expansion in precision equipment. The nylon patch thread locker embedded in the UNF fine threads provides consistent locking force across a broad temperature range (-70° to 250°F), making it ideal for automotive, aerospace, and machinery assemblies where reliability is critical. Its high tensile strength (170,000 psi) and Rockwell C37 hardness ensure durability under cyclic loads, while the socket head design facilitates easy installation in tight spaces, reducing assembly time and improving maintenance efficiency in B2B settings.

Specification Summary & Compliance

This screw features a 1/4"-28 UNF thread with Class 3A fit for precise engagement and fine thread spacing, ensuring accurate alignment in high-tolerance applications. It meets ASME B18.3 and ASTM A574 specifications for dimensional consistency and material properties. Additionally, it is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible sourcing and use in global industrial supply chains.