S-90128A599 5/16"-18 x 4" ASTM A574 Alloy Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional tensile strength of 170,000 psi ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
• Superior corrosion resistance from zinc plating extends service life in harsh industrial environments, minimizing maintenance needs.
• Precise Class 3A thread fit provides tighter tolerances for secure, vibration-resistant assemblies in critical machinery.
• High hardness rating (Rockwell C37) offers excellent wear resistance, maintaining thread integrity through repeated use.
• 1/4" hex drive design allows for easy installation and removal with standard tools, improving assembly efficiency.
• Coarse UNC threading enables faster installation and better performance in materials prone to stripping.
• Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency and environmental safety for global industrial applications.

Professional Applications & Engineering Value

This zinc-plated alloy steel socket head cap screw delivers critical engineering advantages in demanding environments where corrosion resistance and high tensile strength are paramount. The Class 3A thread fit and coarse UNC thread profile provide superior clamping force and vibration resistance in heavy machinery, automotive assemblies, and construction equipment. The partially threaded design concentrates strength where needed most, preventing thread damage during installation while the 1/4" hex drive ensures secure tool engagement. Engineered to withstand extreme mechanical stresses, these socket head cap screws maintain integrity in applications requiring 170,000 psi tensile strength, making them ideal for structural frameworks, manufacturing fixtures, and industrial maintenance where reliability cannot be compromised.

Specification Summary & Compliance

This 5/16"-18 UNC socket head cap screw features precise Class 3A thread fit tolerances with coarse thread spacing and right-hand thread direction. Manufactured to ASTM A574 specification for high-strength alloy steel fasteners, it maintains dimensional accuracy with 4" length and partial threading. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.