S-91263A172 1/4"-20 x 4" ASME B18.3 Alloy Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated alloy steel construction for extended service life in harsh industrial environments
• Exceptional load-bearing capacity with 120,000 PSI tensile strength and Rockwell C32 hardness for heavy-duty applications
• Precise thread engagement with Class 3A thread fit ensuring reliable fastening and vibration resistance
• Optimized installation efficiency featuring UNC coarse threading and 5/32" hex drive for quick assembly
• Flush mounting capability with 82° countersink angle and standard flat head profile for seamless surface integration
• Reduced material stress through controlled partial threading design minimizing component distortion
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations for global supply chain compatibility

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these 1/4"-20 flat head screws deliver critical performance advantages in machinery assembly, structural frameworks, and equipment manufacturing. The zinc-plated alloy steel construction provides essential corrosion protection while maintaining 120,000 PSI tensile strength under sustained loads. The UNC coarse threading with Class 3A thread fit ensures rapid installation and superior vibration resistance, addressing common loosening issues in dynamic environments. The 82° countersink angle enables flush mounting in precision applications where surface clearance is limited. These partially threaded screws concentrate strength where needed most, preventing thread damage during repeated disassembly in maintenance operations.

Specification Summary & Compliance

This 4" flat head screw features precision UNC 1/4"-20 threading with Class 3A thread fit tolerance for exacting dimensional requirements. Manufacturing complies with ASME B18.3 specifications for consistent quality and interchangeability. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety, ensuring environmental responsibility in industrial supply chains.