S-90279A551 1/4"-20 x 2 1/4" ASME B18.6.3 Steel Round Head Phillips Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, ensuring long-term reliability in harsh industrial environments
• Optimized drive engagement through Phillips No. 3 drive design, preventing cam-out and enabling efficient installation
• Precise thread compatibility with Class 2A UNC coarse threads, providing secure fastening and vibration resistance
• Enhanced structural integrity with 60,000 psi tensile strength and Rockwell B69 hardness for demanding applications
• Versatile partial threading allowing unthreaded shank sections for shear load distribution and alignment control
• Industry-standard compliance meeting ASME B18.6.3 specifications for dimensional accuracy and performance reliability
• Environmental responsibility through RoHS 3 and REACH compliance, ensuring safe use across regulated industries

Professional Applications & Engineering Value

These zinc-plated steel rounded head screws deliver exceptional performance in industrial fastening scenarios where corrosion resistance and structural integrity are paramount. The 1/4"-20 UNC coarse thread configuration ensures rapid installation and superior holding power in wood, metal, and composite materials. The partially threaded design provides critical benefits in applications requiring precise clamp load distribution, preventing joint loosening under vibration. With Phillips No. 3 drive compatibility, these screws offer widespread tool accessibility while maintaining torque transmission efficiency. The rounded head profile distributes bearing stress evenly, minimizing surface damage in finished assemblies. Ideal for construction, machinery, and equipment manufacturing, these ASME B18.6.3 compliant fasteners address the engineering need for reliable, standardized components that withstand operational stresses while meeting environmental compliance requirements.

Specification Summary & Compliance

This 1/4"-20 x 2-1/4" rounded head screw features precise Class 2A thread fit tolerances per UNC standards, ensuring consistent engagement and interchangeability. Manufacturing adheres to ASME B18.6.3 specifications for dimensional accuracy and mechanical properties. The product demonstrates full compliance with RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) regulations for chemical safety. With 60,000 psi tensile strength and controlled partial threading, these screws meet rigorous industrial fastening requirements while maintaining regulatory conformity for global supply chain integration.