S-91781A542 1/4"-20 x 1" ASME B18.6.3 Stainless Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel and passivated finish, ideal for harsh environments.
• Exceptional mechanical strength offering 80,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing.
• Precise thread engagement with Class 2A fit and UNC coarse threads, ensuring easy installation and secure fastening.
• Optimized flush mounting due to the standard flat head profile and 82° countersink angle for a smooth surface finish.
• Full-threaded design provides consistent holding power along the entire 1" length for maximum grip.
• Broad industrial compliance meeting ASME B18.6.3, RoHS 3, and REACH standards for safe, regulated use.
• Simple manual installation with a slotted drive style, suitable for standard screwdriver tools.

Professional Applications & Engineering Value

This 1/4"-20 UNC flat head slotted screw is engineered to address common industrial challenges such as corrosion, vibration loosening, and installation precision. Constructed from 18-8 stainless steel with a passivated finish, it resists rust and chemical exposure in demanding settings like marine, food processing, and outdoor equipment. The coarse UNC thread and Class 2A fit reduce cross-threading risks and enable quick assembly, while the fully threaded design ensures uniform stress distribution. Its 82° countersink angle allows for seamless integration into pre-drilled holes, minimizing protrusions in machinery, enclosures, and structural frameworks where a low-profile fastener is critical.

Specification Summary & Compliance

The screw features a 1/4"-20 UNC coarse thread with Class 2A thread fit for standard dimensional accuracy. It is manufactured in compliance with ASME B18.6.3 specifications and adheres to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring it is free from hazardous substances and suitable for global industrial applications.