S-91771A642 3/8"-16 x 4 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with passivated 18-8 stainless steel construction for long-lasting performance in harsh industrial environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness to withstand heavy-duty applications
• Reliable thread engagement with Class 2A thread fit and UNC coarse threads ensuring secure fastening and vibration resistance
• Optimized flush mounting with standard flat head profile and 82° countersink angle for seamless surface integration
• Easy installation with No. 4 Phillips drive providing efficient torque transfer and reduced cam-out risk
• Versatile partial threading allowing precise clamping force control across 1 1/2" minimum thread length
• Full regulatory compliance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

These 3/8"-16 UNC flat head screws deliver critical engineering solutions where surface flushness and corrosion resistance are paramount. The passivated 18-8 stainless steel construction provides exceptional protection against chemical exposure and atmospheric corrosion, making them ideal for marine equipment, food processing machinery, and outdoor structural applications. The partially threaded design ensures optimal clamping force distribution while the coarse UNC threading maintains secure fastening in high-vibration environments. With 80000 psi tensile strength and standardized 82° countersink angle, these screws offer reliable performance in metal fabrication, industrial assembly, and machinery maintenance where dimensional precision and long-term durability are essential.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit and UNC coarse thread specifications. Complies with ASME B18.6.3 mechanical standards for flat head screws. Meets environmental regulations including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance. Features include 4 1/2" overall length, 0.717" head diameter, and right-hand threading with minimum 1 1/2" thread length.