S-91794A578 5/16"-18 x 1/2" ASME B18.6.3 Stainless Steel Fillister Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh environments and long-term reliability.
• Excellent mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications.
• Precise and reliable threading with Class 2A fit and UNC coarse thread profile, ensuring easy installation and secure fastening.
• Optimized head design featuring a high, narrow fillister head with slotted drive for enhanced torque application and a low-profile, rounded appearance.
• Full threading along the 1/2" length provides maximum grip and uniform stress distribution in assembled components.
• Compliance with major standards including ASME B18.6.3, RoHS 3, and REACH, guaranteeing quality and environmental safety.
• Versatile coarse thread (5/16"-18 UNC) enables quick assembly and disassembly, reducing labor time in maintenance and production.

Professional Applications & Engineering Value

This 18-8 stainless steel fillister head slotted screw is engineered to address critical challenges in industrial assembly, such as corrosion-induced failure and thread stripping. The passivated finish significantly enhances the innate corrosion resistance of stainless steel, making it suitable for applications in marine, chemical processing, and outdoor equipment where moisture and chemicals are prevalent. Its high, narrow rounded head (fillister style) offers a deeper slot, allowing for higher torque transmission with standard slotted drivers while maintaining a streamlined profile to prevent snagging. The coarse UNC thread and Class 2A thread fit ensure rapid installation and robust holding power, reducing the risk of cross-threading in high-vibration environments like machinery, automotive subsystems, and electrical enclosures. By combining material durability with precision threading, this screw minimizes maintenance downtime and extends service life in heavy-duty fastening scenarios.

Specification Summary & Compliance

This screw adheres to precise dimensional and performance criteria: Thread Fit Class 2A per UNC standards, 5/16"-18 thread size with coarse spacing, and a total length of 1/2". It is manufactured in compliance with ASME B18.6.3 specifications for slotted head screws. The product is confirmed to be RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring it meets stringent environmental and safety regulations for hazardous substances.