S-90128A123 4-40 x 1 1/2" ASTM A574 Alloy Steel Socket Head Screws

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.
• Zinc-plated alloy steel construction provides excellent corrosion resistance, extending service life and maintaining integrity in harsh industrial environments.
• Class 3A thread fit offers superior precision and tighter tolerances, enabling secure fastening with minimal backlash in critical assemblies.
• Partially threaded design with 3/4" minimum thread length allows for optimal grip and alignment, simplifying installation in varied material thicknesses.
• Hex drive socket head with 3/32" drive size facilitates easy installation and removal using standard tools, improving maintenance efficiency.
• Compliance with ASTM A574, RoHS 3, and REACH standards ensures material quality, environmental safety, and suitability for global industrial use.
• Rockwell C37 hardness enhances durability and wear resistance, supporting long-term reliability in repetitive or high-vibration settings.

Professional Applications & Engineering Value

This 4-40 UNC thread socket head cap screw is engineered to address common industrial challenges, such as vibration-induced loosening and corrosion in machinery. The zinc-plated alloy steel material combats rust and wear, while the coarse thread spacing and Class 3A fit provide secure, repeatable fastening in equipment like automotive assemblies, electronic enclosures, and precision tools. Its partially threaded rod type and right-hand thread direction enable quick alignment and stable connections, reducing assembly time and maintenance costs. Ideal for applications requiring high-strength fasteners, this screw ensures consistent performance, backed by rigorous standards for industrial reliability.

Specification Summary & Compliance

This product adheres to precise dimensional tolerances, including Class 3A thread fit and UNC thread type with coarse spacing, ensuring compatibility with standard components. It meets ASTM A574 specifications for material and manufacturing quality, and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for environmental and industrial use without hazardous substances.