S-90550A130 2-56 x 3/8" 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 long-term reliability.
• Enhanced fastening precision through Class 3A thread fit and UNC coarse threads, ensuring tight, secure connections with reduced risk of cross-threading.
• Efficient installation and removal with the hex drive design, allowing for high torque application and minimizing tool slippage.
• Optimal flush mounting thanks to the standard flat head profile and 82° countersink angle, providing a smooth, finished surface.
• Reliable pressure equalization via the vented screw feature, preventing pressure buildup in sensitive assemblies.
• Full-length thread engagement across the 3/8" length, maximizing grip strength and load distribution in various materials.
• Compliance with major industry standards including ASME B18.3, ASTM F879, and MIL-DTL-18240, guaranteeing consistent quality and performance.

Professional Applications & Engineering Value

This 2-56 UNC flat head screw is engineered to address critical challenges in precision assembly and corrosive environments. The 18-8 stainless steel material provides excellent resistance to oxidation and chemical exposure, making it suitable for electronics, aerospace, and marine applications where durability is paramount. The hex drive and fully threaded design ensure quick, secure fastening with minimal cam-out, while the vented feature allows for pressure relief in sealed units, preventing failure due to differential pressure. Its UNC coarse thread and Class 3A fit offer superior holding power in metals and plastics, reducing the need for frequent maintenance. Ideal for industrial fastening that demands reliability under stress, this screw combines material strength with precision manufacturing to enhance product lifespan and safety.

Specification Summary & Compliance

This screw adheres to strict dimensional tolerances, including a Class 3A thread fit for high-precision applications and UNC coarse threading (2-56 size) with a length of 3/8". It meets ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring consistency with industry manufacturing norms. Additionally, it is fully RoHS 3 (2015/863/EU) compliant and REACH (EC 1907/2006) compliant, supporting environmental and safety standards for global supply chains.