S-91772A939 1/4"-20 x 3 1/4" 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
• Enhanced assembly efficiency through the combination of partially threaded design and coarse UNC threads for faster installation
• Reliable high-strength performance with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Secure and stable fastening ensured by Class 2A thread fit, providing consistent engagement and vibration resistance
• Optimized drive engagement with Phillips No. 3 drive style, reducing cam-out and improving torque transfer
• Broad compliance and safety meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH
• Versatile pan head design offering a low-profile, rounded head that sits flush and distributes load evenly

Professional Applications & Engineering Value

These 1/4-20 UNC partially threaded pan head screws are engineered to address critical industrial fastening challenges. The passivated 18-8 stainless steel provides exceptional resistance to corrosion and oxidation, making them suitable for applications in chemical processing, marine equipment, and food machinery where moisture and corrosive agents are present. The partially threaded design allows for precise clamping force concentration, preventing joint loosening in vibrating environments while the coarse UNC thread facilitates quick assembly in softer materials or when alignment is challenging. Combined with the Phillips No. 3 drive, these screws deliver reliable installation with reduced tool slippage, enhancing worker safety and productivity in assembly lines and maintenance operations.

Specification Summary & Compliance

This screw features precision Class 2A thread fit according to UNC standards, ensuring consistent threading and proper engagement. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its safety for use in regulated industries and commitment to environmental standards.