S-90343A112 4-40 x 3/8" ASME B18.3 18-8 Stainless Steel Thread-Locking Socket Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments
• High tensile strength of 70,000 psi ensures reliable performance under heavy loads and vibration
• Pre-applied epoxy thread locker prevents loosening in temperatures from -60° to 300°F, reducing maintenance needs
• Precise Class 3A thread fit delivers consistent engagement and reduces assembly errors
• Durable Rockwell B70 hardness provides excellent wear resistance and long service life
• Hex socket drive design allows for easy installation in confined spaces with standard tools
• Full threading along the 3/8" length offers maximum adjustability and holding power

Professional Applications & Engineering Value

This 4-40 UNC thread socket head cap screw is engineered to address critical challenges in precision assemblies, such as machinery, automotive components, and electronic enclosures. The 18-8 stainless steel material combats corrosion and oxidation, extending service life in demanding conditions. With a coarse thread spacing and Class 3A fit, it ensures quick, secure fastening without cross-threading, while the epoxy thread locker actively resists vibration-induced loosening. Its hex drive and compact socket head facilitate efficient installation in tight spaces, making it a reliable choice for OEM and MRO applications where durability and precision are paramount.

Specification Summary & Compliance

This screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for high precision. It features UNC coarse threads, a 3/8" length, and fully threaded design. The epoxy adhesive meets typical industrial requirements, and the material complies with common standards for stainless steel fasteners, ensuring consistent quality and performance in regulated environments.