S-90279A078 2-56 x 5/16" ASME B18.6.3 Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• Enhanced durability and wear resistance from Rockwell B69 hardness, ensuring reliable performance under mechanical stress
• Quick and secure installation with No. 1 Phillips drive and fully threaded UNC coarse design, reducing assembly time
• Consistent thread engagement through Class 2A thread fit, minimizing cross-threading and improving joint integrity
• Broad compatibility with standard 2-56 UNC components, facilitating easy integration into existing assemblies
• Environmental compliance assurance meeting RoHS 3 and REACH regulations, supporting sustainable manufacturing practices
• Optimized head design with rounded profile for reduced snagging and improved aesthetic finish in visible applications

Professional Applications & Engineering Value

These zinc-plated steel rounded head screws deliver exceptional value in industrial fastening applications where corrosion resistance and mechanical reliability are critical. The 2-56 UNC coarse thread configuration provides excellent holding power in softer materials and rapid installation, while the fully threaded design ensures maximum engagement along the entire 5/16" length. The No. 1 Phillips drive offers familiar, tool-friendly installation without specialized equipment, making these ASME B18.6.3 compliant fasteners ideal for electronics enclosures, machinery panels, and automotive components where vibration resistance and long-term performance are essential. The combination of zinc plating and steel substrate creates a protective barrier against oxidation, significantly extending service life in humid or chemically exposed environments.

Specification Summary & Compliance

This fastener maintains Class 2A thread fit tolerance per UNC standards, ensuring consistent threading performance and interchangeability. Manufacturing complies with ASME B18.6.3 specifications for dimensional accuracy and mechanical properties. Environmental compliance includes RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming restriction of hazardous substances. The right-hand threaded configuration with coarse thread spacing provides optimal performance in most industrial assembly applications.