S-91771A542 1/4"-20 x 1" 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 and outdoor applications.
• High tensile strength of 80,000 psi ensures reliable performance under heavy loads and mechanical stress.
• Rockwell B80 hardness provides excellent durability and resistance to wear over extended use.
• Fully threaded UNC coarse design delivers faster installation and stronger holding power in a variety of materials.
• Standard 82° countersink angle allows for a flush, professional finish that minimizes snagging and improves safety.
• Class 2A thread fit ensures consistent, reliable engagement with standard nuts and tapped holes.
• Phillips No. 3 drive offers common tool compatibility and efficient torque transfer during assembly.

Professional Applications & Engineering Value

Engineered for demanding industrial settings, these 1/4"-20 UNC coarse thread flat head screws provide a robust fastening solution where corrosion resistance and high tensile strength are critical. The passivated 18-8 stainless steel material effectively resists oxidation and chemical exposure, making these screws ideal for machinery, marine equipment, and structural assemblies exposed to moisture or corrosive agents. The fully threaded right-hand design with a standard 82° countersink angle ensures a secure, flush fit that reduces protrusion risks and maintains aerodynamic or aesthetic surfaces. Commonly used in metal fabrication, automotive, and construction industries, these flat head Phillips screws deliver reliable performance, reducing maintenance frequency and enhancing the longevity of assembled components.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with Class 2A thread fit for precise dimensional accuracy and consistent performance. Manufactured in compliance with ASME B18.6.3 specifications, ensuring adherence to industry standards for mechanical and dimensional requirements. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, confirming it meets strict environmental and safety regulations for hazardous substances.