S-90471A446 1/4"-20 x 1 3/4" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding environments
• High tensile strength of 60,000 psi ensures reliable fastening under heavy loads and vibration
• Rockwell B70 hardness provides excellent wear resistance and prevents thread deformation during installation
• Class 2A thread fit offers optimal assembly clearance while maintaining secure connections
• 100° countersink angle enables flush mounting for cleaner finishes and reduced snag hazards
• Fully threaded design maximizes grip length and distributes stress evenly across the fastener
• Phillips No. 3 drive delivers efficient torque transfer with widely available driving tools

Professional Applications & Engineering Value

These zinc-plated steel flat head screws solve critical challenges in industrial assembly where flush surface mounting and corrosion resistance are paramount. The 1/4"-20 UNC coarse thread configuration provides rapid installation in metal, wood, and composite materials while resisting vibration-induced loosening. With 60,000 psi tensile strength and Rockwell B70 hardness, these fully threaded screws maintain integrity in structural applications, electrical enclosures, machinery guards, and automotive components. The standard flat head profile with 100° countersink angle ensures seamless integration while the Phillips No. 3 drive accommodates high-volume production environments.

Specification Summary & Compliance

Manufactured to ASME B18.6.3 specifications with Class 2A thread fit tolerances for consistent performance. The 1/4"-20 UNC coarse thread maintains proper engagement while the 1 3/4" length provides versatile fastening depth. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.