S-90403A083 2-56 x 1/2" ASME B18.13 Steel Pan Head Phillips Screws with Internal-Tooth Lock Washer

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• Reliable vibration resistance through integrated internal-tooth lock washers that maintain secure fastening under dynamic loads
• Optimized installation efficiency with Phillips No. 1 drive and coarse UNC threading for quick assembly and reduced operator fatigue
• Exceptional mechanical strength delivering 60,000 psi tensile strength and Rockwell B69 hardness for high-stress applications
• Precise thread engagement with Class 2A thread fit ensuring consistent performance and compatibility with standard components
• Full-thread design providing maximum grip length and uniform load distribution across the entire fastener
• Regulatory compliance assurance meeting ASME B18.13 specifications while being RoHS 3 and REACH compliant for global applications

Professional Applications & Engineering Value

These zinc-plated steel rounded head screws with internal-tooth lock washers provide critical vibration-resistant fastening solutions for industrial machinery, electronic enclosures, and automotive assemblies. The 2-56 UNC coarse thread configuration ensures rapid installation while maintaining Class 2A thread fit precision for consistent performance in high-cycle production environments. The combination of 60,000 psi tensile strength and Rockwell B69 hardness delivers reliable clamping force retention in applications subject to thermal cycling and mechanical stress. The fully threaded design maximizes surface contact area, distributing loads evenly to prevent joint failure in critical industrial screw applications where vibration loosening poses significant operational risks.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerance and UNC coarse thread spacing per ASME B18.13 specifications. These 1/2" length screws feature fully threaded construction with zinc-plated steel material throughout both screw and integrated lock washer. Compliance verified with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring suitability for global industrial markets and restricted substance-free manufacturing processes.