S-90279A108 4-40 x 3/8" ASME B18.6.3 Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• Maximum holding power achieved through fully threaded design and Class 2A thread fit for reliable fastening performance
• High tensile strength rating of 60,000 psi ensures dependable performance under mechanical stress and vibration
• Rockwell B69 hardness provides excellent durability and resistance to wear during installation and use
• Easy installation and removal with Phillips No. 1 drive and rounded head design for improved tool engagement
• Industry-standard compliance with ASME B18.6.3 specifications ensures consistent quality and interchangeability
• Environmental regulation compliance with RoHS 3 and REACH standards for safe use across global markets

Professional Applications & Engineering Value

These 4-40 UNC zinc-plated steel screws with rounded head Phillips drive deliver exceptional engineering value across industrial applications. The combination of zinc-plated steel material and coarse thread design provides superior corrosion resistance while maintaining easy installation in various materials. The fully threaded configuration ensures maximum grip length and holding power, making them ideal for machinery assembly, electronic enclosures, and equipment manufacturing where vibration resistance is critical. With 3/8" length and Class 2A thread fit, these screws offer precise dimensional accuracy for consistent performance in automated assembly processes. The Rockwell B69 hardness rating ensures the fastener maintains structural integrity during repeated installation cycles, reducing replacement costs and downtime in production environments.

Specification Summary & Compliance

This 4-40 UNC screw features precise Class 2A thread fit per ASME B18.6.3 standards, ensuring dimensional accuracy and interchangeability. The product meets ASME B18.6.3 manufacturing specifications for machine screws and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. The coarse thread spacing and right-hand thread direction provide reliable fastening performance across industrial applications while maintaining full regulatory compliance for global distribution.