S-91205A565 1/4"-28 x 1" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking: Integrated nylon patch thread locker maintains secure fastening in high-vibration environments from -70° to 250°F
• Precision thread engagement: Class 3A thread fit ensures superior dimensional accuracy and reliable mating with UNF fine-threaded components
• Exceptional load capacity: 170,000 psi tensile strength provides reliable performance under extreme mechanical stress
• Durable corrosion protection: Black-oxide finish on alloy steel substrate offers enhanced resistance to oxidation and wear
• Optimized drive efficiency: Standard socket head with 3/16" hex drive enables high-torque installation in confined spaces
• Industry-standard compliance: Manufactured to ASME B18.3 and ASTM A574 specifications for guaranteed interchangeability
• Full-thread engagement: 1" fully threaded design maximizes contact area for superior clamping force distribution

Professional Applications & Engineering Value

These black-oxide alloy steel socket head cap screws deliver critical performance in demanding applications where vibration resistance and precision threading are paramount. The Class 3A UNF fine threads provide superior engagement in tapped holes, reducing the risk of cross-threading while the nylon patch thread locker eliminates the need for separate locking components in assembly operations. Engineered for machinery, automotive, and heavy equipment applications, the 170,000 psi tensile strength and Rockwell C37 hardness ensure reliable fastening in high-stress environments. The combination of alloy steel construction with black-oxide surface treatment offers excellent durability against corrosion while maintaining the dimensional stability required for precision assemblies.

Specification Summary & Compliance

Manufactured to ASME B18.3 dimensional standards with material certification to ASTM A574, these socket head cap screws feature Class 3A thread fit for precision UNF fine threading applications. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations ensures suitability for global industrial markets. The 1/4"-28 UNF thread configuration with right-hand orientation provides standardized compatibility across industrial fastener systems.