S-94063A063 4-40 x 1/4" ASME B18.6.3 Tamper-Resistant Drilled Spanner Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Enhanced tamper resistance through drilled spanner drive design, providing additional security for critical assemblies
• Reliable thread engagement with Class 2A thread fit ensuring consistent performance and easy installation
• Optimal flush mounting featuring undercut flat head profile that sits perfectly flush with surfaces
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Industry-standard compatibility with UNC coarse threading and 82° countersink angle meeting common engineering requirements
• Full regulatory compliance meeting ASME B18.6.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

These 4-40 UNC flat head spanner screws provide exceptional engineering value in precision applications where flush mounting and tamper resistance are critical. The combination of 18-8 stainless steel material and passivated finish creates a robust corrosion-resistant solution ideal for electronic enclosures, aerospace components, and medical devices exposed to challenging environments. The undercut flat head profile ensures perfect surface alignment while the drilled spanner drive offers secure fastening in spaces where standard drives are impractical. With fully threaded construction and Class 2A thread fit, these screws deliver reliable performance in vibration-prone assemblies, maintaining integrity under mechanical stress with their 70,000 psi tensile strength.

Specification Summary & Compliance

These flat head screws feature precise Class 2A thread fit with UNC coarse thread spacing and right-hand threading. Manufacturing adheres to ASME B18.6.3 specifications with dimensional accuracy including head diameter tolerance of -0.03" to 0". The products are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets.