S-93791A569 1/4"-20 x 1 1/4" ASME B18.3 Stainless Steel Hex Drive Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance from 18-8 stainless steel construction and black-oxide passivated finish, ideal for harsh industrial environments
• Exceptional holding power with 70,000 psi tensile strength and Rockwell B55 hardness for reliable, long-term fastening performance
• Precision thread engagement through UNC coarse threading with Class 3A fit, ensuring secure connections and reduced cross-threading risk
• Flush mounting capability with standard 82° countersink angle and flat head design for smooth surface finishes
• Easy installation and removal with 5/32" hex drive, providing superior torque transmission compared to slotted drives
• Full-length threading offering maximum grip along the entire 1-1/4" length for versatile application needs
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

This black-oxide 18-8 stainless steel flat head screw delivers exceptional engineering value in demanding industrial applications where corrosion resistance and structural integrity are paramount. The combination of UNC coarse threading with Class 3A thread fit provides superior engagement in various materials, reducing installation time while maintaining precise tolerance control. The black-oxide passivated finish enhances surface durability and provides additional protection against chemical exposure and atmospheric conditions. The 82° countersink angle ensures proper seating in standard chamfered holes, creating flush surfaces that prevent snagging and improve aesthetic appeal. These fully threaded screws are particularly valuable in machinery assembly, electrical enclosures, and structural frameworks where vibration resistance and long-term reliability are critical requirements.

Specification Summary & Compliance

This high-performance fastener features precision UNC 1/4"-20 coarse threading with Class 3A thread fit for superior dimensional accuracy and engagement. Manufacturing complies with ASME B18.3 specifications for flat head screw geometry and performance standards. The product is fully RoHS 3 (2015/863/EU) compliant and meets REACH (EC 1907/2006) requirements regarding substance restrictions, ensuring environmental responsibility and regulatory adherence for global industrial applications.