S-91790A105 4-40 x 1/4" ASME B18.6.3 Stainless Steel Slotted Oval Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh environments
• Exceptional tensile strength rated at 80,000 psi for reliable performance in demanding applications
• Precise Class 2A thread fit ensures smooth installation and consistent fastening engagement
• Standard oval head profile with slotted drive provides attractive finish and easy manual installation
• Full threading along entire 1/4" length delivers maximum grip and holding power
• Coarse UNC threading enables quick assembly and reduced cross-threading risk
• Comprehensive compliance with ASME B18.6.3, RoHS 3, and REACH for quality assurance

Professional Applications & Engineering Value

This 4-40 UNC oval head slotted screw delivers exceptional engineering value across industrial applications where corrosion resistance and reliable fastening are critical. The 18-8 stainless steel material combined with passivated finish provides superior protection against oxidation and chemical exposure, making these flat head screws ideal for marine equipment, food processing machinery, and outdoor installations. The coarse thread design and Class 2A thread fit ensure rapid installation while minimizing the risk of cross-threading in production environments. With 80,000 psi tensile strength and Rockwell B80 hardness, these fasteners maintain integrity under vibration and load stress, providing long-term reliability in mechanical assemblies, electronic enclosures, and precision equipment where consistent performance is mandatory.

Specification Summary & Compliance

This 4-40 UNC oval head slotted screw features precise Class 2A thread fit with coarse threading and right-hand thread direction. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and performance standards. The product is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, meeting current environmental regulations for hazardous substances. Additional specifications include 82° countersink angle and fully threaded 1/4" length construction.