S-90585A202 4-40 x 3/8" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction and passivated finish for extended service life in harsh environments
• Precise flush mounting with standard 82° countersink angle and flat head design for seamless surface integration
• Exceptional mechanical strength delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding applications
• Reliable thread engagement with Class 3A fit and UNC coarse threads ensuring secure fastening in various materials
• Easy installation and removal with 1/16" hex drive providing positive torque transmission
• Full thread coverage along the entire 3/8" length for maximum grip and load distribution
• Industry compliance assurance meeting ASME B18.3 specifications for dimensional accuracy and performance

Professional Applications & Engineering Value

These 4-40 UNC flat head screws in 316 stainless steel provide critical solutions for applications where corrosion resistance and mechanical reliability are paramount. The combination of passivated finish and marine-grade stainless steel makes them ideal for chemical processing equipment, marine hardware, and food processing machinery where exposure to moisture and corrosive agents is constant. The Class 3A thread fit ensures precise engagement in tapped holes, reducing the risk of cross-threading while the coarse UNC thread form provides excellent holding power in softer materials. The hex drive configuration allows for high-torque installation without cam-out issues, making them particularly valuable in assembly lines where consistent fastening performance is essential. These screws deliver engineering value through their ability to maintain integrity in temperature-variable environments while meeting strict industry standards for dimensional accuracy.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 specifications with Class 3A thread fit tolerance for superior dimensional accuracy. The UNC coarse thread (4-40) with right-hand direction and full threading along the 3/8" length ensures reliable performance. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations guarantees these screws meet international standards for restricted substances, making them suitable for global supply chains and sensitive applications.