S-91205A560 1/4"-28 x 1/2" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent nylon patch thread locker prevents loosening under dynamic loads, ensuring long-term joint integrity.
• Exceptional tensile strength of 170,000 psi provides reliable performance in high-stress industrial applications and heavy machinery assemblies.
• Corrosion-resistant black-oxide finish on alloy steel enhances durability and offers protection in demanding environments.
• Precision Class 3A thread fit guarantees smooth installation and secure fastening with minimal risk of cross-threading.
• Wide temperature tolerance from -70° to 250° F maintains locking performance and material integrity in extreme operating conditions.
• Standard hex socket drive allows for high-torque installation with common tools, facilitating efficient assembly and maintenance.
• Full threading along the 1/2" length offers versatile positioning and uniform clamping force across the entire fastener.

Professional Applications & Engineering Value

Engineered for precision and reliability, these 1/4"-28 UNF socket head cap screws are integral in applications where vibration resistance and high strength are critical. The black-oxide alloy steel construction, combined with a permanent nylon patch thread locker, effectively counters common issues like bolt loosening in machinery, automotive, and aerospace assemblies. The fine thread spacing and Class 3A thread fit ensure tight tolerances, reducing the risk of failure in dynamic environments. Ideal for securing components in engines, industrial equipment, and electronic enclosures, these screws deliver consistent performance, minimizing maintenance needs and enhancing operational safety. Their compliance with ASME B18.3 and material standards like ASTM A574 further underscores their suitability for rigorous engineering demands.

Specification Summary & Compliance

This socket head cap screw adheres to Class 3A thread fit for precise engagement and is manufactured in accordance with ASME B18.3 and ASTM A574 specifications. It features a UNF fine thread with a size of 1/4"-28 and is fully threaded for uniform load distribution. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it meets environmental and safety standards for industrial use.