S-91771A948 8-32 x 3/8" 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 washdown applications.
• High tensile strength of 80,000 psi ensures reliable load-bearing capacity and joint integrity in demanding mechanical assemblies.
• Rockwell B80 hardness provides excellent durability and resistance to wear, reducing the risk of stripping or head deformation.
• Class 2A thread fit with UNC coarse threading offers smooth installation and consistent engagement, minimizing cross-threading risks.
• 100° countersink angle and flat head design allows for a flush, secure fit that eliminates protrusions and improves aerodynamics in assembled products.
• Phillips No. 2 drive enables efficient, widespread tool compatibility for faster installation and reduced assembly time.
• Full threading along the 3/8" length ensures maximum grip and uniform stress distribution across the entire fastened joint.

Professional Applications & Engineering Value

This 8-32 flat head screw is engineered to address common industrial challenges such as vibration loosening, corrosion-induced failure, and installation inefficiency. The passivated 18-8 stainless steel provides a robust barrier against oxidation and chemical exposure, making it suitable for outdoor equipment, marine hardware, and food processing machinery where moisture and cleaning agents are present. The UNC coarse thread design enhances thread engagement in softer materials or pre-tapped holes, reducing the likelihood of stripping. Combined with the flat head profile and 100° countersink, it delivers a seamless finish that meets aesthetic and functional requirements in automotive, aerospace, and electronics enclosures. These features collectively improve assembly reliability, extend service life, and lower total cost of ownership.

Specification Summary & Compliance

This machine screw adheres to ASME B18.6.3 specifications, ensuring dimensional accuracy and interchangeability. The thread fit is Class 2A, providing standard manufacturing tolerances for consistent performance. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming the absence of restricted hazardous substances. The screw features a right-hand thread direction, UNC coarse thread pattern, and a length of 3/8", meeting industry standards for reliable fastening in professional and industrial applications.