S-97763A318 4-40 x 1/8" ASME B18.3 Stainless Steel Button Head Hex-Drive Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to Black-Oxide 18-8 Stainless Steel construction, ideal for harsh industrial environments
• Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness for reliable, long-lasting fastening
• Precision thread engagement with Class 3A thread fit ensuring secure, vibration-resistant connections in critical assemblies
• Easy installation and removal with hex drive design and 1/16" drive size for efficient tool access in confined spaces
• Full threading versatility providing maximum grip along the entire 1/8" length for uniform clamping force distribution
• Regulatory compliance assurance meeting ASME B18.3 standards while being RoHS 3 and REACH compliant for global applications
• Optimized head design with rounded button profile reducing surface protrusion and preventing snagging in moving components

Professional Applications & Engineering Value

These 4-40 UNC thread rounded head screws deliver critical performance advantages in precision engineering applications where corrosion resistance and mechanical reliability are paramount. The Black-Oxide 18-8 Stainless Steel construction provides enhanced protection against oxidation and chemical exposure, making these hex drive screws ideal for electronics enclosures, medical devices, and marine equipment. The Class 3A thread fit ensures tight tolerances for vibration-prone assemblies, while the fully threaded design offers consistent load distribution across the entire fastener length. The combination of 70,000 psi tensile strength and coarse thread spacing provides superior pull-out resistance in both metallic and composite materials, solving common challenges of fastener loosening and material stripping in high-stress industrial environments.

Specification Summary & Compliance

These industrial fasteners feature precision 4-40 UNC coarse threads with Class 3A thread fit for superior dimensional accuracy. Manufacturing complies with ASME B18.3 specifications, ensuring consistent quality and interchangeability. The screws are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, making them suitable for global supply chains and environmentally sensitive applications. Additional specifications include right-hand thread direction, fully threaded design, and standardized rounded button head profile for consistent performance across industrial applications.