S-91781A541 1/4"-20 x 7/8" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ensuring long-term reliability in harsh environments
• Exceptional tensile strength rated at 80,000 psi for secure, vibration-resistant fastening in demanding applications
• Precise Class 2A thread fit with UNC coarse threading for easier alignment and reduced cross-threading risk during installation
• 82° countersink angle with standard flat head profile for flush mounting and clean aesthetic finish
• Full threading design provides maximum grip length and uniform load distribution across the entire fastener
• Rockwell B80 hardness maintains structural integrity under mechanical stress and repeated use
• Comprehensive compliance with ASME B18.6.3 manufacturing standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

These 1/4-20 UNC flat head slotted screws deliver critical performance advantages for industrial applications where corrosion resistance and reliable fastening are paramount. The 18-8 stainless steel composition, enhanced by passivated finish, provides exceptional protection against oxidation and chemical exposure, making them ideal for marine equipment, food processing machinery, and outdoor structures. The coarse thread spacing and Class 2A thread fit ensure quick installation with reduced galling, while the 82° countersink angle allows for flush mounting in precision assemblies. With 80,000 psi tensile strength and full threading, these flat head screws maintain joint integrity under vibration and dynamic loads, solving common failure points in heavy-duty mechanical systems.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit and UNC coarse thread spacing, these screws guarantee consistent performance and interchangeability. The product fully complies with ASME B18.6.3 specifications for dimensional accuracy and mechanical properties. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring safe use across various industries without hazardous substance restrictions.