S-90117A116 4-40 x 1/4" ASME B18.3 Alloy Steel Wire-Lockable Socket Head Screws

Key Features & Benefits at a Glance

• Superior tensile strength (170,000 psi) ensures reliable performance under high-stress conditions, reducing the risk of fastener failure in demanding applications.
• Precision Class 3A thread fit guarantees tight, secure connections with minimal play, enhancing assembly accuracy and vibration resistance.
• Black-oxide finish on alloy steel provides excellent corrosion resistance, extending service life in harsh industrial environments.
• Wire locking design in the socket head prevents unintentional loosening, maintaining clamp load and improving operational safety.
• High hardness (Rockwell C37) offers exceptional wear resistance, ensuring durability through repeated installation and removal cycles.
• Coarse UNC threads enable quick and easy installation, reducing assembly time and labor costs in production lines.
• Compact 3/32" hex drive and standard socket profile allow for easy access in confined spaces, simplifying maintenance and repairs.

Professional Applications & Engineering Value

This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in precision machinery, automotive assemblies, and heavy-duty equipment. The 4-40 UNC coarse thread with Class 3A fit ensures minimal tolerance deviations, crucial for applications requiring exact alignment and vibration resistance, such as in aerospace components or electronic enclosures. The wire locking feature secures the screw against rotational forces, preventing downtime in dynamic environments. Made from high-strength alloy steel with a protective black-oxide coating, it combats corrosion and wear, making it ideal for outdoor or chemically exposed settings. Its fully threaded design and 1/4" length provide uniform clamping force, essential for maintaining structural integrity in compact assemblies.

Specification Summary & Compliance

This screw features a 4-40 UNC coarse thread with Class 3A precision fit, ensuring tight dimensional accuracy per ASME B18.3 standards. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for global industrial use without hazardous substances. Manufactured to meet rigorous mechanical properties, including a tensile strength of 170,000 psi and Rockwell C37 hardness, it adheres to quality benchmarks for reliable performance in critical fastening applications.