S-90273A583 5/16"-18 x 1" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction for extended service life in demanding environments
• Exceptional mechanical strength with 60,000 psi tensile strength and Rockwell B70 hardness for heavy-duty applications
• Reliable thread engagement with Class 2A fit and UNC coarse threads ensuring secure fastening and vibration resistance
• Streamlined installation featuring standard 82° countersink angle for flush mounting and Phillips No. 4 drive for efficient assembly
• Full-threaded design providing maximum grip length and uniform stress distribution across the entire fastener
• Regulatory compliance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH
• Precision manufacturing ensuring consistent dimensional accuracy with right-hand threading and inch system measurements

Professional Applications & Engineering Value

These zinc-plated steel flat head screws deliver critical performance advantages in industrial fastening applications where corrosion resistance, mechanical strength, and regulatory compliance are paramount. The UNC coarse thread configuration provides excellent engagement in various materials while resisting vibration-induced loosening. The standard 82° countersink angle ensures proper seating in chamfered holes, creating flush surfaces essential for machinery, equipment assembly, and structural applications. With full threading along the entire 1" length, these screws distribute clamping force evenly, reducing stress concentration points. The Phillips No. 4 drive facilitates efficient installation in high-volume production environments, while the zinc plating offers sacrificial protection against environmental degradation, making these fasteners ideal for outdoor equipment, manufacturing machinery, and industrial maintenance applications.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerance ensuring consistent performance across applications. Complies with ASME B18.6.3 mechanical and dimensional specifications for flat head screws. Meets environmental regulations including RoHS 3 (2015/863/EU) compliance for restricted substances and REACH (EC 1907/2006) requirements. Features right-hand UNC 5/16"-18 coarse threads with standard thread spacing, manufactured from zinc-plated steel with Rockwell B70 hardness rating and 60,000 psi tensile strength capability.