S-91321A112 4-40 x 1/4" MS35190-221, NASM35190 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced corrosion resistance through cadmium plating for extended service life in demanding industrial environments
• Superior holding power with 60,000 psi tensile strength ensuring reliable fastening in critical applications
• Precision thread engagement with Class 2A fit providing consistent installation and vibration resistance
• Optimized flush mounting with standard 82° countersink angle for seamless surface integration
• Efficient installation using No. 1 Phillips drive design for quick assembly and disassembly
• Full-thread coverage along the 1/4" length maximizes grip strength and load distribution
• Industry-standard compliance with MS35190-221 specifications ensures quality and interchangeability

Professional Applications & Engineering Value

These cadmium-plated steel flat head screws deliver exceptional engineering value in applications where surface flushness and corrosion resistance are critical. The 4-40 UNC coarse thread configuration provides excellent pull-out resistance in softer materials while maintaining easy installation. The fully threaded design ensures maximum engagement depth, making them ideal for thin-section assemblies in electronics, aerospace components, and precision machinery. The 82° countersink angle creates a clean, flush finish that eliminates protrusions in sensitive applications. Manufactured to meet MS35190-221 specifications, these Phillips flat head screws offer reliable performance in environments requiring strict compliance with military and industrial standards.

Specification Summary & Compliance

This 4-40 UNC flat head screw features Class 2A thread fit tolerance ensuring precise engagement and consistent performance. The product complies with MS35190-221 (NASM35190) specifications and incorporates right-hand coarse threading with full thread coverage along the 1/4" length. The cadmium-plated steel construction meets industry standards for corrosion protection while delivering 60,000 psi tensile strength. The standard 82° flat head profile and No. 1 Phillips drive are engineered to exact dimensional requirements for reliable performance in industrial fastening applications.