S-91772A138 4-40 x 3" ASME B18.6.3 Stainless Steel Pan Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments.
• High tensile strength of 70,000 psi ensures reliable, long-lasting fastening under demanding loads.
• Rockwell B70 hardness provides excellent durability and resistance to wear and deformation.
• Partially threaded design allows for precise clamping force and reduced risk of cross-threading.
• Class 2A thread fit with UNC coarse threading ensures easy assembly and consistent performance.
• Phillips drive (No. 1) offers secure, efficient installation with standard tools.
• Compliance with ASME B18.6.3, RoHS 3, and REACH guarantees quality, safety, and environmental standards.

Professional Applications & Engineering Value

These 4-40 UNC partially threaded pan head screws are engineered to address common industrial challenges, such as vibration loosening and corrosion in demanding applications. Made from passivated 18-8 stainless steel, they provide exceptional resistance to rust and chemicals, making them ideal for machinery, electronics, and outdoor equipment. The coarse UNC threading and Class 2A fit ensure quick, secure installations with minimal effort, while the partially threaded design allows for optimal grip and stress distribution. With a Phillips drive for easy tool compatibility, these screws deliver reliable performance in assembly lines, automotive, and aerospace sectors, reducing maintenance costs and downtime.

Specification Summary & Compliance

This screw features a 4-40 UNC thread size with Class 2A thread fit and coarse thread spacing, ensuring precise dimensional accuracy per industry standards. It meets ASME B18.6.3 specifications for mechanical and dimensional requirements, and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and safe for various applications.