S-91794A540 1/4"-20 x 3/4" ASME B18.6.3 Stainless Steel Fillister Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to the 18-8 stainless steel material and passivated finish, ensuring long-term reliability in harsh environments.
• High-strength performance with a tensile strength of 70,000 psi and Rockwell B55 hardness, providing dependable load-bearing capacity for demanding applications.
• Excellent thread engagement from the UNC coarse thread and Class 2A fit, enabling quick installation and secure fastening with reduced cross-threading risk.
• Optimized head design featuring a high, narrow fillister profile for increased drive torque and a slotted drive for simple tool compatibility.
• Full threading along the 3/4" length ensures consistent grip and uniform stress distribution across the entire fastener.
• Compliance with industry standards including ASME B18.6.3, RoHS 3, and REACH, guaranteeing quality, safety, and environmental responsibility.
• Right-hand thread direction for standard installation practices, facilitating ease of use in assembly lines.

Professional Applications & Engineering Value

This 18-8 stainless steel fillister head screw is engineered to address critical industrial fastening challenges, such as vibration loosening and environmental degradation. The passivated finish enhances its innate corrosion resistance, making it ideal for applications in moist or chemically aggressive settings, including marine equipment, food processing machinery, and outdoor structures. Its high, narrow rounded head provides a deeper slot, allowing for higher torque application without stripping, which is essential in assemblies requiring precise clamping force. The 1/4"-20 UNC coarse thread ensures rapid installation and robust holding power in materials like metal and hard plastics, reducing assembly time while maintaining joint integrity. By combining 70,000 psi tensile strength with full threading, this screw delivers uniform stress distribution, minimizing the risk of fatigue failure in dynamic load conditions.

Specification Summary & Compliance

This screw adheres to precise dimensional tolerances, including a Class 2A thread fit for consistent engagement and the UNC coarse thread series per ASME B18.6.3 specifications. It is manufactured in the inch system with a diameter of 0.25" and length of 3/4", ensuring compatibility with standard components. Compliance is verified with ASME B18.6.3 for mechanical and dimensional standards, RoHS 3 (2015/863/EU) for restricted substance limits, and REACH (EC 1907/2006) for chemical safety, supporting use in regulated industries.