S-90665A175 5/16"-18 x 1/2" ASTM A574 Alloy Steel Low-Profile Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional Tensile Strength – With a 140,000 psi rating, these screws provide superior load-bearing capacity and resistance to mechanical failure in demanding applications.
• Enhanced Corrosion Resistance – The zinc-plated alloy steel construction offers reliable protection against rust and environmental degradation, extending service life.
• Precise Thread Fit – Class 3A thread ensures tight, secure fastening with minimal backlash, ideal for high-vibration and precision assemblies.
• Low-Profile Socket Head Design – Allows for installation in confined spaces while the hex drive provides high torque transmission without stripping.
• High Hardness & Durability – Rockwell C39 hardness ensures the screw maintains its shape and thread integrity under repeated use and stress.
• Compliance with Industry Standards – Meets ASTM A574 specifications, ensuring consistent quality, performance, and material integrity.
• Environmental & Safety Compliance – RoHS 3 and REACH compliant, making them suitable for use in regulated industries and eco-conscious projects.

Professional Applications & Engineering Value

These zinc-plated alloy steel socket head cap screws are engineered to address critical challenges in industrial and mechanical assemblies. The 5/16"-18 UNC coarse thread and Class 3A fit provide excellent engagement and vibration resistance, reducing the risk of loosening in machinery, automotive, and construction applications. The low-profile socket head with a hex drive allows for easy installation in tight spaces, while the fully threaded design ensures uniform clamping force. Combined with 140,000 psi tensile strength and corrosion-resistant plating, these screws deliver long-term reliability, minimizing maintenance and downtime in harsh operating environments.

Specification Summary & Compliance

This socket head cap screw features a 5/16"-18 UNC coarse thread with a Class 3A thread fit for precise, high-strength fastening. It complies with ASTM A574 manufacturing standards, ensuring dimensional accuracy and material consistency. The product is also verified to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for industrial use.