S-90008A431 4-40 x 3/8" ASME B18.3, ASTM F837 18-8 Stainless Steel Socket Head Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with silver-plated 18-8 stainless steel construction for extended service life in harsh environments
• Superior mechanical strength with 70,000 psi tensile strength and Rockwell B70 hardness to withstand high-stress applications
• Precise thread engagement through Class 3A thread fit ensuring reliable fastening and vibration resistance
• Optimized drive performance with hex socket design providing maximum torque transfer and reduced cam-out risk
• Regulatory compliance assurance meeting ASME B18.3 specifications and environmental standards including RoHS 3 and REACH
• Versatile coarse threading with 4-40 UNC configuration enabling quick assembly and disassembly in various materials
• Full-thread design offering consistent gripping strength along the entire 3/8" length for uniform load distribution

Professional Applications & Engineering Value

Engineered for demanding industrial applications, these socket head cap screws combine the corrosion-resistant properties of silver-plated 18-8 stainless steel with high-strength mechanical performance. The 4-40 UNC coarse thread configuration provides excellent holding power in soft materials and rapid installation capabilities, while the Class 3A thread fit ensures precise tolerances for critical assemblies. The hex drive socket design allows for high-torque installation in confined spaces, making these fasteners ideal for precision equipment, machinery, and electronic enclosures where reliability and corrosion resistance are paramount. The combination of 70,000 psi tensile strength and Rockwell B70 hardness ensures these screws maintain integrity under sustained mechanical stress.

Specification Summary & Compliance

Manufactured to exacting ASME B18.3 specifications with Class 3A thread fit tolerances for superior precision. The 4-40 UNC coarse thread configuration follows standardized inch system measurements. These socket head cap screws are fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across various industries. The fully threaded design and right-hand thread direction provide consistent performance in alignment with industrial fastener standards.