S-91771A554 1/4"-20 x 3" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with passivated 18-8 stainless steel, ideal for harsh industrial environments and extending service life.
• High tensile strength of 80,000 psi ensures reliable performance under heavy loads, reducing the risk of fastener failure.
• Rockwell B80 hardness provides excellent durability and resistance to wear, maintaining integrity in demanding applications.
• Partially threaded UNC coarse thread design allows for easier alignment and faster assembly, improving installation efficiency.
• Phillips No. 3 drive and standard flat head profile offer secure, flush mounting and reduced risk of cam-out during tightening.
• Compliance with ASME B18.6.3 standards guarantees dimensional accuracy and interchangeability, ensuring consistent quality.
• RoHS 3 and REACH compliant for environmentally safe use, meeting global regulatory requirements in various industries.

Professional Applications & Engineering Value

This 1/4"-20 UNC flat head screw is engineered to address common industrial challenges, such as vibration loosening and corrosion in machinery assemblies. The passivated 18-8 stainless steel material provides superior resistance to rust and chemicals, making it ideal for applications in automotive, construction, and marine equipment where exposure to moisture is frequent. The partially threaded design with UNC coarse threads ensures quick and secure fastening in metals and plastics, reducing installation time and improving structural stability. Combined with a Phillips No. 3 drive and flat head profile, it enables flush surface mounting, minimizing protrusions and enhancing safety in tight spaces. This screw delivers reliable performance in heavy-duty fastening, supporting long-term operational efficiency and reducing maintenance costs.

Specification Summary & Compliance

This product adheres to Class 2A thread fit for precise dimensional tolerance and smooth assembly, with UNC coarse thread specifications ensuring compatibility in various applications. It meets ASME B18.6.3 manufacturing standards for consistency and reliability. Additionally, it is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmentally responsible and safe usage in industrial settings.