S-91321A113 4-40 x 3/8" MS35190-223, NASM35190 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with cadmium-plated steel construction, ensuring long-term reliability in demanding industrial environments.
• High tensile strength of 60,000 psi provides exceptional load-bearing capacity and prevents fastener failure under stress.
• Fully threaded UNC coarse design enables faster installation and superior grip in a wide range of materials.
• Precise Class 2A thread fit guarantees consistent, secure engagement and reduces the risk of cross-threading during assembly.
• Standard 82° countersink angle allows for a flush, professional finish that minimizes protrusion and improves safety.
• Phillips No. 1 drive offers widespread tool compatibility and efficient torque transfer for quick and easy installation.
• Compliance with MS35190-223 (NASM35190) ensures adherence to rigorous aerospace and industrial quality standards.

Professional Applications & Engineering Value

Engineered for precision and durability, these 4-40 UNC flat head screws are ideal for applications where space constraints and surface finish are critical. The cadmium-plated steel provides excellent corrosion protection, extending service life in harsh conditions such as aerospace assemblies, electronic enclosures, and machinery panels. The fully threaded coarse UNC design ensures rapid installation and strong holding power in both metal and composite substrates, reducing assembly time and labor costs. With a standard 82° countersink angle and flat head profile, these screws sit flush to prevent snagging and maintain aerodynamic or aesthetic surfaces. This combination of high tensile strength (60,000 psi) and reliable Phillips drive makes them a trusted choice for OEMs and maintenance teams seeking consistent performance and compliance with MS35190-223 specifications.

Specification Summary & Compliance

This product adheres to precise dimensional standards, including Class 2A thread fit for consistent engagement and UNC coarse threading (4-40) with right-hand direction. The screw features a head diameter of 0.225", length of 3/8", and is fully threaded for maximum grip. It complies with MS35190-223 (NASM35190) specifications, ensuring quality and reliability for industrial and aerospace applications. Materials and processes are selected to meet common industry requirements, though specific RoHS or REACH declarations should be verified per batch.