S-96640A055 4-40 x 5/16" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide 18-8 Stainless Steel construction, ideal for harsh environments and extended service life.
• High tensile strength of 80,000 psi ensures reliable performance under heavy loads and vibration, reducing failure risks.
• Class 2A thread fit provides consistent, easy assembly with standard UNC coarse threads, minimizing cross-threading and improving installation efficiency.
• Fully threaded design offers maximum grip and holding power along the entire shank for secure fastening in various materials.
• 82° countersink angle and flat head profile allow for a flush, low-profile finish, enhancing aesthetics and safety in assembled products.
• Phillips No. 1 drive enables quick and secure tool engagement, speeding up production and reducing driver slippage.
• Compliance with ASME B18.6.3, RoHS 3, and REACH guarantees adherence to industry standards and environmental regulations, ensuring safe and reliable use.

Professional Applications & Engineering Value

These 4-40 UNC flat head Phillips screws are engineered to address common industrial challenges such as corrosion, vibration loosening, and assembly precision. The Black-Oxide 18-8 Stainless Steel material provides excellent resistance to rust and oxidation, making them suitable for outdoor equipment, marine applications, and electronic enclosures where moisture exposure is a concern. The fully threaded UNC coarse thread design ensures strong engagement in metals and plastics, while the 82° countersink angle allows for seamless integration into countersunk holes, preventing protrusions that could interfere with moving parts or aesthetics. With a Rockwell B80 hardness and high tensile strength, these screws maintain integrity under stress, reducing maintenance needs and downtime in machinery, automotive, and aerospace assemblies. Their compliance with ASME B18.6.3 standards further assures dimensional accuracy and reliability for critical fastening tasks.

Specification Summary & Compliance

This product features precise dimensions including a 5/16" length, 0.212" head diameter, and Class 2A thread fit for consistent UNC coarse threading. It meets ASME B18.6.3 specifications for flat head screws, ensuring interoperability and quality. Additionally, it is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming adherence to environmental and safety regulations for hazardous substances.