S-92210A557 1/4"-20 x 3 1/2" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable performance under heavy loads
• Precise Class 3A thread fit ensures secure fastening with minimal vibration loosening in critical applications
• Efficient hex drive installation with 5/32" drive size providing maximum torque transfer and reduced tool slippage
• Optimal flush mounting with standard 82° countersink angle and flat head design for smooth surface finishing
• Full threading coverage along the 3-1/2" length enables consistent clamping force across the entire engagement area
• Regulatory compliance assurance meeting ASME B18.3 standards while being RoHS 3 and REACH compliant for global industrial use

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these 1/4"-20 UNC flat head screws solve critical fastening challenges where corrosion resistance and structural integrity are paramount. The 18-8 stainless steel composition combined with passivated finish provides exceptional protection against chemical exposure and atmospheric corrosion, making them ideal for marine equipment, food processing machinery, and outdoor structural applications. The coarse thread design ensures rapid installation in various materials while maintaining superior pull-out resistance. The hex drive configuration delivers reliable torque transmission during assembly, preventing cam-out issues common in Phillips drives. These fully threaded fasteners distribute clamping force evenly, eliminating stress concentration points that can lead to material fatigue in heavy-duty applications.

Specification Summary & Compliance

This flat head screw maintains precise Class 3A thread fit with UNC coarse thread profile (1/4"-20) and right-hand threading direction. Manufacturing conforms to ASME B18.3 specifications with dimensional accuracy including 0.531" head diameter, 0.161" head height, and standard flat head profile. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global industrial markets.