S-91781A540 1/4"-20 x 3/4" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 Stainless Steel construction and passivated finish, ideal for harsh industrial environments
• Superior holding power from fully threaded 1/4"-20 UNC coarse threads that resist loosening under vibration
• High tensile strength of 80,000 psi ensures reliable performance in demanding structural applications
• Precise flush mounting with standard 82° countersink angle and flat head design for seamless surface integration
• Consistent thread quality with Class 2A fit providing smooth assembly and reliable engagement
• Enhanced durability with Rockwell B80 hardness for long service life and reduced wear
• Comprehensive compliance meeting ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

This 18-8 Stainless Steel flat head screw delivers exceptional engineering value through its optimized material properties and fully threaded UNC coarse thread design. The combination of 80,000 psi tensile strength and Rockwell B80 hardness ensures reliable performance in high-stress applications where fastener failure is not an option. The passivated finish provides superior corrosion resistance, making these slotted screws ideal for machinery, industrial equipment, and outdoor applications exposed to moisture and chemicals. The standard 82° countersink angle allows for perfect flush mounting in metal fabrication, woodworking, and assembly operations where surface smoothness is critical. These industrial screws solve common fastening challenges by maintaining integrity in corrosive environments while providing consistent Class 2A thread fit for efficient installation and long-term reliability.

Specification Summary & Compliance

This flat head screw features precision 1/4"-20 UNC coarse threads with Class 2A thread fit ensuring consistent dimensional accuracy and reliable assembly. Manufactured to ASME B18.6.3 specifications with complete RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance, meeting the latest environmental and safety standards. The right-hand thread direction and fully threaded design provide maximum engagement strength across the entire 3/4" length, while the standardized dimensions guarantee interchangeability and replacement compatibility in industrial fastening systems.