S-90344A119 5/16"-18 x 1" ASME B18.3, ASTM A574 Socket Head Screws with Flat Washer

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress industrial applications, reducing the risk of fastener failure.
• Superior corrosion resistance from the black-oxide finish on both the alloy steel screw and washer, extending service life in harsh environments.
• Precise Class 3A thread fit with UNC coarse threads provides secure, vibration-resistant fastening and easier assembly in demanding conditions.
• Integrated flat washer distributes load evenly, minimizing surface damage and improving joint integrity under dynamic loads.
• High hardness (Rockwell C39) offers excellent wear resistance, maintaining thread integrity through repeated use and adjustments.
• 1/4" hex drive socket head allows for high-torque installation with standard tools, ensuring tight, secure fits in confined spaces.
• Full compliance with ASME B18.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental safety, supporting global supply chain requirements.

Professional Applications & Engineering Value

Engineered for heavy-duty industrial applications, this black-oxide alloy steel socket head cap screw with an integrated flat washer addresses critical challenges in machinery, automotive, and construction assemblies. The UNC coarse thread design and Class 3A thread fit enhance grip and resistance to loosening under vibration, while the 170,000 psi tensile strength and Rockwell C39 hardness ensure durability in high-load scenarios. The black-oxide surface treatment on both the screw and washer provides reliable corrosion resistance, reducing maintenance needs in corrosive environments. Its right-hand threading and fully threaded rod enable efficient installation and consistent clamping force, making it ideal for precision equipment and structural frameworks where reliability is paramount.

Specification Summary & Compliance

This socket head cap screw features precise Class 3A thread fit with UNC coarse threads (5/16"-18 size) and a 1" length, manufactured to ASME B18.3 specifications using ASTM A574 material. It complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity for industrial use.