S-91771A546 1/4"-20 x 1 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, ensuring long-term reliability in harsh industrial environments
• Exceptional tensile strength of 80,000 PSI provides reliable fastening for heavy-duty applications requiring maximum load-bearing capacity
• Optimized drive engagement with Phillips No. 3 drive style prevents cam-out and ensures secure installation with standard tools
• Precision UNC coarse threading with Class 2A fit enables quick assembly and superior vibration resistance in demanding applications
• Flush mounting capability with 82° countersink angle and standard flat head profile creates smooth, professional finishes
• Full threading design along the entire 1-1/2" length provides maximum grip and uniform stress distribution
• Consistent performance backed by Rockwell B80 hardness rating, maintaining dimensional stability under mechanical stress

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these flat head Phillips screws deliver exceptional value through their passivated 18-8 stainless steel composition, which provides superior resistance to corrosion and chemical exposure. The UNC coarse threading with Class 2A fit ensures rapid installation and reliable performance in vibration-prone environments, while the 82° countersink angle facilitates flush mounting in precision assemblies. The combination of 80,000 PSI tensile strength and Rockwell B80 hardness makes these fasteners ideal for machinery, equipment manufacturing, and structural applications where durability and reliability are critical. The fully threaded design maximizes engagement surface area, distributing stress evenly to prevent joint failure in heavy-duty fastening scenarios.

Specification Summary & Compliance

Manufactured to exacting standards with Class 2A thread fit tolerance and UNC thread specifications ensuring precise dimensional accuracy. These flat head screws comply with ASME B18.6.3 manufacturing standards and meet critical regulatory requirements including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) environmental regulations. The inch system measurement and right-hand thread direction provide compatibility with standard industrial applications and tooling systems.