S-91773A559 1/4"-28 x 3/4" ASME B18.6.3 Stainless Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Exceptional mechanical strength with 100,000 psi tensile strength and Rockwell B100 hardness for reliable performance under heavy loads
• Precise thread engagement with UNF fine threads and Class 2A fit ensuring secure fastening and vibration resistance
• Optimized drive performance featuring Phillips No. 3 drive for efficient installation and reduced cam-out risk
• Full-threaded design providing maximum grip length and uniform stress distribution along the entire fastener
• Industry-standard compliance meeting ASME B18.6.3 specifications for dimensional accuracy and interchangeability
• Environmental responsibility with RoHS 3 and REACH compliance, free from restricted hazardous substances

Professional Applications & Engineering Value

This 18-8 stainless steel rounded head Phillips screw delivers critical performance advantages for demanding industrial applications. The combination of UNF fine threading and Class 2A fit provides superior vibration resistance in machinery, automotive assemblies, and precision equipment where loosening under dynamic loads is a concern. The passivated finish enhances the natural corrosion resistance of stainless steel, making these screws ideal for environments exposed to moisture, chemicals, or outdoor conditions. With 100,000 psi tensile strength and full threading along the 3/4" length, these fasteners distribute clamping forces evenly, preventing joint failure in high-stress applications. The rounded head profile and Phillips drive ensure flush mounting and efficient installation in confined spaces.

Specification Summary & Compliance

This fastener features precise 1/4"-28 UNF fine threads with Class 2A tolerance for consistent fit and performance. Manufactured to ASME B18.6.3 dimensional standards, ensuring interchangeability and reliability. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming the absence of restricted hazardous substances. The fully threaded design provides maximum engagement while maintaining the specified mechanical properties throughout the fastener length.