S-91783A571 1/4"-20 x 3 1/2" ASME B18.6.3 Stainless Steel Round Head Slotted 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 mechanical strength with 100,000 psi tensile strength and Rockwell B100 hardness for heavy-duty applications
• Reliable coarse threading with UNC 1/4"-20 pattern and Class 2A fit for quick assembly and vibration resistance
• Optimized partial threading design providing secure fastening while minimizing material stress concentration
• Standard slotted drive compatibility with rounded head profile for universal tool access and streamlined installation
• Full regulatory compliance meeting ASME B18.6.3 specifications plus RoHS 3 and REACH environmental standards
• Precision dimensional control with 3½" length and 1½" minimum thread length for consistent performance across applications

Professional Applications & Engineering Value

Engineered for demanding industrial environments, these 18-8 stainless steel rounded head screws combine material excellence with precision manufacturing to address critical fastening challenges. The passivated finish significantly enhances corrosion resistance in chemical processing, marine, and food equipment applications where moisture and corrosive agents are present. The UNC coarse thread pattern with Class 2A fit ensures rapid installation and maintains clamping force under vibration, making these partially threaded screws ideal for machinery assembly, structural frameworks, and equipment manufacturing. The slotted drive system with rounded head profile accommodates standard tools while providing a finished appearance, delivering both functional performance and aesthetic considerations for OEM and MRO applications requiring ASME B18.6.3 compliance.

Specification Summary & Compliance

This 1/4"-20 UNC slotted screw features precise Class 2A thread fit tolerances with coarse thread spacing and right-hand threading. Manufacturing conforms to ASME B18.6.3 specifications for dimensional accuracy and performance standards. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental responsibility and chemical safety. Critical dimensions include 3½" overall length with 1½" minimum thread length, 0.472" head diameter, and standardized rounded head profile for consistent interface performance.