S-91249A107 4-40 x 5/16" ASME B18.6.3 Stainless Steel Pan Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with Black-Oxide coated 18-8 Stainless Steel, ideal for harsh industrial environments
• High tensile strength of 70,000 psi ensures reliable load-bearing capacity and reduces failure risks
• Rockwell B70 hardness provides excellent wear resistance and long-term durability
• Class 2A thread fit guarantees precise, easy assembly and consistent performance in repetitive applications
• Fully threaded design maximizes grip and distribution of clamping force across the entire length
• Phillips No. 1 drive allows for efficient installation with standard tools, reducing assembly time
• Compliance with ASME B18.6.3, RoHS 3, and REACH ensures safety, quality, and environmental standards are met

Professional Applications & Engineering Value

These 4-40 UNC coarse thread machine screws are engineered for precision and reliability in demanding industrial settings. The Black-Oxide 18-8 Stainless Steel construction offers enhanced corrosion resistance, making them suitable for applications exposed to moisture, chemicals, or outdoor elements. The rounded pan head with Phillips drive ensures secure, flush mounting without snagging, while the fully threaded design provides uniform stress distribution, preventing loosening under vibration. Commonly used in electronics, machinery, and automotive assemblies, these screws address critical needs for durability, ease of installation, and compliance with stringent industry regulations, reducing maintenance costs and downtime.

Specification Summary & Compliance

This screw features a 4-40 UNC coarse thread with Class 2A thread fit for precise tolerances, a length of 5/16 inch, and a right-hand thread direction. It conforms to ASME B18.6.3 manufacturing standards and is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity.