S-95635A261 4-40 x 1/4" ASME B18.3 Tamper-Resistant Hex-Drive Stainless Steel Button Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with specialized hex drive requiring unique tools, preventing unauthorized access in sensitive applications
• Superior corrosion protection through 18-8 stainless steel construction and passivated surface treatment for extended service life
• Exceptional mechanical strength delivering 70,000 psi tensile strength and Rockwell B70 hardness for reliable performance under stress
• Precision thread engagement with Class 3A fit and UNC coarse threading ensuring secure fastening in various materials
• Optimized head design featuring rounded button profile for reduced snagging and improved aesthetic integration
• Full threading capability providing maximum grip length and uniform load distribution across the entire fastener
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH

Professional Applications & Engineering Value

These 4-40 UNC thread rounded head screws deliver critical security and reliability in demanding industrial environments. The 18-8 stainless steel composition combined with passivated finish provides exceptional resistance to corrosion, oxidation, and chemical exposure, making them ideal for electronics enclosures, medical devices, and outdoor equipment. The tamper-resistant hex drive design specifically addresses vulnerability concerns in public-access installations while maintaining the installation efficiency of standard hex drives. With Class 3A thread fit and coarse thread spacing, these fasteners ensure rapid assembly and secure mating in both metallic and non-metallic substrates, reducing installation time while preventing loosening from vibration. The fully threaded configuration maximizes engagement depth, providing superior pull-out resistance in applications where material thickness varies.

Specification Summary & Compliance

Manufactured to precise dimensional standards with Class 3A thread fit tolerance and UNC coarse thread specifications. These rounded head screws comply with ASME B18.3 mechanical and dimensional requirements, ensuring interchangeability and reliability. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) certifications, confirming restriction of hazardous substances. The 1/4" length and 4-40 thread size maintain consistent performance across production batches with 70000 psi tensile strength and Rockwell B70 hardness validated through quality control processes.