S-91400A850 1/4"-28 x 1/2" FF-S-92, QQ-P-35, MS51958-79, NASM51958 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 environments and extended service life
• High tensile strength of 80,000 PSI ensures reliable performance under heavy loads and vibration
• Fine UNF threading with Class 2A fit provides precise engagement and reduced risk of cross-threading in critical assemblies
• Fully threaded design offers maximum grip and uniform clamping force across the entire length
• Phillips #3 drive and pan head profile enable efficient installation with standard tools and a low-profile, rounded finish
• Compliance with major industry standards including Fed. Spec. FF-S-92 and NASM51958, ensuring interchangeability and quality consistency
• RoHS 3 and REACH environmental compliance meets global regulatory requirements for hazardous substance restrictions

Professional Applications & Engineering Value

This 1/4"-28 UNF pan head screw delivers exceptional value in applications demanding corrosion resistance and mechanical reliability. The passivated 18-8 stainless steel material prevents oxidation and chemical degradation, making it suitable for marine, chemical processing, and outdoor equipment. The fine thread and Class 2A fit provide superior vibration resistance and precise alignment in assemblies such as electronic enclosures, machinery guards, and automotive components. Its fully threaded design ensures consistent load distribution, reducing stress concentrations. With a Phillips #3 drive, installation is streamlined for maintenance and production lines, while the rounded pan head offers a clean, snag-free profile. These features collectively address common industrial challenges like fastener failure, corrosion-induced downtime, and assembly inaccuracies.

Specification Summary & Compliance

This screw adheres to precise dimensional standards with a UNF 1/4"-28 thread size, Class 2A thread fit for consistent tolerance, and a length of 1/2 inch. It conforms to specifications including Fed. Spec. FF-S-92, QQ-P-35, MS51958-79, and NASM51958. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from restricted substances and safe for various industrial and commercial applications.