S-90273A114 4-40 x 7/8" ASME B18.6.3 Steel Phillips Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• High tensile strength of 60,000 psi ensures reliable fastening under substantial mechanical loads and vibrations
• Class 2A thread fit provides consistent, reliable engagement with standard UNC coarse threaded components
• Fully threaded design offers maximum grip and holding power across the entire 7/8" length
• 82° countersink angle enables flush mounting for clean, professional finishes in assembled products
• Phillips drive (No. 1 size) allows for efficient installation with common industrial tools while minimizing cam-out
• Rockwell B70 hardness maintains thread integrity and prevents stripping during repeated installation cycles

Professional Applications & Engineering Value

These 4-40 UNC flat head screws deliver exceptional engineering value in precision assembly applications where space constraints and surface finish are critical. The zinc-plated steel construction provides essential corrosion protection for electronic enclosures, machinery panels, and automotive components exposed to moderate environmental conditions. The coarse UNC threading ensures rapid installation and superior resistance to vibration loosening compared to fine-thread alternatives. The standard 82° countersink angle allows for seamless integration with chamfered holes, eliminating protrusions that could interfere with moving parts or compromise aesthetic requirements. These fully threaded fasteners maintain consistent clamping force across their entire length, making them ideal for securing sheet metal, plastic components, and thin materials where maximum thread engagement is essential for structural integrity.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 2A thread fit tolerances ensuring compatibility with standard UNC threaded components. These screws conform to ASME B18.6.3 specifications for dimensional accuracy and mechanical properties. Compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations ensures environmental responsibility and safe use across global markets. The combination of 60,000 psi tensile strength and Rockwell B70 hardness guarantees performance reliability in industrial fastening applications.