S-90550A740 1/4"-20 x 3/4" ASME B18.3, ASTM F879, MIL-DTL-18240 Venting Stainless Steel Hex-Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and outdoor applications.
• Exceptional thread engagement and reliability due to Class 3A fit UNC coarse threads, reducing the risk of cross-threading and ensuring secure fastening.
• Efficient installation and removal with a 5/32" hex drive, providing a positive grip for high-torque applications without cam-out.
• Flush, professional finish achieved with an 82° countersink angle and standard flat head profile, suitable for applications requiring a smooth surface.
• Enhanced durability in demanding conditions with full threading and vented design, allowing for consistent performance and pressure equalization.
• Broad industry compatibility by meeting ASME B18.3, ASTM F879, and MIL-DTL-18240 standards, ensuring quality and interchangeability.
• Safe for regulated environments with compliance to RoHS 3 and REACH, supporting sustainable and health-conscious manufacturing practices.

Professional Applications & Engineering Value

This 1/4-20 UNC flat head screw in 18-8 stainless steel is engineered to address common industrial fastening challenges, such as corrosion in humid or chemical-exposed settings. Its coarse threading and Class 3A fit provide quick assembly and high resistance to vibration loosening, making it ideal for machinery, automotive, and construction applications. The hex drive ensures easy installation in tight spaces, while the 82° countersink angle allows for a seamless fit in pre-drilled holes, reducing surface protrusion. Fully threaded and vented, it offers reliable performance in assemblies requiring pressure management, enhancing longevity and reducing maintenance costs in industrial flat head screw uses.

Specification Summary & Compliance

This screw maintains precise Class 3A thread fit per UNC standards, with a length of 3/4" and full threading for consistent engagement. It conforms to ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring dimensional accuracy and reliability. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting environmental and safety regulations for global supply chains.