S-91099A481 1/4"-20 x 1 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from passivated 18-8 stainless steel, ensuring longevity in harsh industrial environments
• High tensile strength of 80,000 psi provides reliable load-bearing capacity for demanding applications
• Precise Class 2A thread fit guarantees smooth installation and secure fastening with UNC coarse threading
• Optimized Phillips No. 3 drive design enables efficient torque transfer and reduces cam-out during installation
• 82° undercut flat head profile allows for flush mounting and improved aesthetic finish in countersunk applications
• Full threading along the 1-1/2" length ensures maximum grip and uniform stress distribution
• Compliance with ASME B18.6.3, RoHS 3, and REACH assures quality consistency and environmental responsibility

Professional Applications & Engineering Value

This 1/4"-20 flat head screw delivers exceptional engineering value through its passivated 18-8 stainless steel construction, specifically engineered to address common industrial challenges. The material's inherent corrosion resistance, enhanced by passivation, prevents rust and degradation in moisture-prone environments, making it ideal for outdoor equipment, marine hardware, and chemical processing installations. The UNC coarse thread with Class 2A fit ensures rapid assembly and vibration resistance in high-stress applications, while the flat head with undercut provides a seamless finish that eliminates protrusion hazards. With 80,000 psi tensile strength and Rockwell B80 hardness, it maintains structural integrity under heavy loads, offering reliable performance in machinery assembly, structural frameworks, and automotive components where durability and precision are critical.

Specification Summary & Compliance

This fastener features precision 1/4"-20 UNC coarse threads with Class 2A thread fit for consistent engagement and dimensional accuracy. Manufacturing and quality adhere to ASME B18.6.3 specifications, ensuring interchangeability and performance reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted hazardous substances and supporting sustainable procurement practices in industrial supply chains.