S-91790A539 1/4"-20 x 5/8" ASME B18.6.3 Stainless Steel Slotted Oval 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 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
• Optimized thread engagement through Class 2A UNC coarse threading ensures secure fastening and vibration resistance
• Industry-standard compliance with ASME B18.6.3 specifications guarantees dimensional accuracy and interchangeability
• Enhanced flush mounting capability with standard oval head profile and 82° countersink angle for clean, professional installations
• Environmental regulation compliance meeting RoHS 3 and REACH standards for safe, sustainable industrial use
• Simplified installation and maintenance with slotted drive design and fully threaded shank for straightforward assembly

Professional Applications & Engineering Value

This 18-8 stainless steel oval head screw delivers critical performance advantages for demanding industrial applications where corrosion resistance and mechanical reliability are paramount. The combination of UNC coarse threading and Class 2A thread fit provides excellent engagement in various materials while resisting loosening under vibration. The passivated finish enhances the natural corrosion resistance of stainless steel, making these flat head screws ideal for marine equipment, food processing machinery, chemical processing plants, and outdoor infrastructure. The oval head design with 82° countersink creates a smooth, flush surface finish while the slotted drive accommodates traditional installation tools. With 80,000 psi tensile strength, these fasteners maintain structural integrity in high-stress assemblies, providing engineers with a dependable industrial fastener solution that meets rigorous ASME B18.6.3 standards.

Specification Summary & Compliance

This 1/4"-20 x 5/8" stainless steel oval head screw features precise UNC coarse threading with Class 2A thread fit tolerance for consistent performance. Manufactured in compliance with ASME B18.6.3 specifications for dimensional accuracy and mechanical properties. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industrial sectors. The right-hand thread direction and fully threaded design provide complete engagement throughout the fastener length.