S-90344A115 1/4"-20 x 3/4" 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 under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Superior corrosion resistance from the black-oxide finish on alloy steel, extending service life and maintaining integrity in harsh industrial environments.
• Precise Class 3A thread fit with UNC coarse threading provides secure, vibration-resistant connections, minimizing loosening in machinery and equipment.
• Integrated flat washer distributes load evenly, preventing surface damage and enhancing joint stability for long-term reliability.
• High hardness rating (Rockwell C39) offers excellent wear resistance, maintaining thread integrity through repeated assembly and disassembly cycles.
• Hex socket drive design allows for high-torque installation with standard tools, facilitating efficient assembly in confined spaces.
• Full threading along the 3/4" length ensures maximum grip and adjustability, suitable for a wide range of material thicknesses.

Professional Applications & Engineering Value

This black-oxide alloy steel socket head cap screw is engineered to address critical challenges in industrial settings, such as vibration-induced loosening and corrosion. The UNC coarse thread and Class 3A fit provide superior holding power in metals and plastics, making it ideal for machinery, automotive assemblies, and heavy equipment where reliability is paramount. The inclusion of a flat washer enhances load distribution, reducing stress concentrations on softer materials. With its high tensile strength and Rockwell C39 hardness, this fastener withstands dynamic loads and harsh conditions, ensuring long-term performance in applications like precision tooling, conveyor systems, and structural frameworks.

Specification Summary & Compliance

This socket head cap screw features a 1/4"-20 UNC thread with Class 3A fit for precise dimensional accuracy, ensuring consistent performance in assembly operations. Manufactured to meet ASME B18.3 specifications and constructed from alloy steel, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental and safety standards for global industrial use. The integrated flat washer (1/2" OD, 1/16" thickness) is made from black-oxide steel, complementing the screw's durability and corrosion resistance.