S-91771A933 4-40 x 3/16" 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 environments
• Exceptional mechanical strength with 80,000 psi tensile strength and Rockwell B80 hardness for demanding industrial applications
• Precision thread engagement through Class 2A fit and UNC coarse threading, providing secure fastening and vibration resistance
• Optimized flush mounting with standard 100° countersink angle and flat head design for seamless surface integration
• Enhanced drive stability with Phillips No. 1 drive style, reducing cam-out and improving installation efficiency
• Full-threaded design ensuring maximum grip length and uniform load distribution across the entire 3/16" length
• Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations for global industrial use

Professional Applications & Engineering Value

These 4-40 UNC flat head screws deliver critical performance advantages in precision assembly applications where corrosion resistance and flush surface requirements are paramount. The passivated 18-8 stainless steel construction provides exceptional protection against oxidation and chemical exposure, making them ideal for electronics enclosures, machinery panels, and marine equipment. The fully threaded right-hand coarse spacing ensures rapid installation and superior holding power in materials where thread stripping is a concern. With Phillips drive compatibility and standardized 100° countersink angle, these screws facilitate efficient assembly while maintaining clean aesthetic finishes in consumer products, industrial controls, and aerospace components where surface discontinuity is unacceptable.

Specification Summary & Compliance

Manufactured to exacting Class 2A thread fit tolerances with UNC coarse thread spacing (4-40), these flat head screws maintain dimensional precision per ASME B18.6.3 specifications. The 3/16" length and standardized head dimensions ensure consistent performance across applications. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations guarantees environmental safety and unrestricted use in global markets, while the right-hand threading and fully threaded design provide reliable fastening performance in automated and manual assembly processes.