S-91771A634 3/8"-16 x 2 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments.
• Exceptional mechanical strength offering 80,000 psi tensile strength and Rockwell B80 hardness for reliable, heavy-duty applications.
• Precise Class 2A thread fit ensures smooth assembly and secure fastening in coarse UNC threads.
• Optimized flush mounting with an 82° countersink angle and standard flat head profile for seamless surface integration.
• Enhanced drive stability provided by Phillips No. 4 drive style, reducing cam-out during installation.
• Versatile partial threading allows for controlled clamping force in construction and machinery assemblies.
• Full regulatory compliance with ASME B18.6.3, RoHS 3, and REACH standards for safe, global use.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 3/8"-16 UNC flat head Phillips screws deliver outstanding performance in construction, machinery, and structural applications. The passivated 18-8 stainless steel provides excellent resistance to oxidation and chemical exposure, extending service life in corrosive environments. With a coarse thread design and partial threading, these screws offer superior grip and reduced risk of over-tightening, ensuring stable connections in metal, wood, and composite materials. The 82° countersink angle and flat head design enable flush installation, minimizing protrusion and enhancing safety in high-traffic areas. Ideal for assembly lines, outdoor equipment, and heavy-duty frameworks, these screws address common challenges like vibration loosening and material fatigue, providing a reliable, long-term fastening solution.

Specification Summary & Compliance

This product adheres to Class 2A thread fit tolerances and UNC coarse thread standards, ensuring consistent dimensional accuracy. Manufactured in compliance with ASME B18.6.3 specifications, it meets rigorous mechanical and design criteria. The screw is fully RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, confirming its suitability for environmentally conscious and regulated industries. Key dimensions include a 2 1/2" length, 0.717" head diameter, and 1 1/2" minimum thread length, supporting precise application requirements.