S-90337A397 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction for long-lasting performance in harsh environments
• Exceptional surface hardness and wear resistance from TiCN coating, extending service life and reducing maintenance frequency
• Precise component alignment through controlled shoulder diameter (1/8") and length (7/8") with tight tolerances
• Reliable thread engagement with Class 2A UNC coarse threads ensuring consistent fastening in vibration-prone applications
• Space-saving low-profile socket head with 5/64" hex drive for installations with limited clearance
• High mechanical strength delivering 70,000 psi tensile strength and Rockwell B55 hardness for demanding loads
• Regulatory compliance assurance meeting RoHS 3 and REACH standards for global industrial applications

Professional Applications & Engineering Value

This precision shoulder screw addresses critical alignment and durability challenges in industrial machinery, automation systems, and precision instruments. The 18-8 stainless steel base material provides inherent corrosion resistance, while the TiCN coating significantly enhances surface hardness to 3000+ Vickers, preventing galling and wear in high-cycle applications. The precise shoulder fit with minimal diameter tolerance (-0.001" to 0") ensures accurate component positioning, eliminating misalignment in assemblies. The low profile socket head design allows installation in confined spaces where standard socket heads cannot fit, while the UNC coarse threads provide rapid assembly and superior vibration resistance. These features make it ideal for precision equipment, robotic arms, and manufacturing jigs where repeated accuracy and durability are paramount.

Specification Summary & Compliance

Manufactured to exacting standards, this shoulder screw maintains Class 2A thread fit per UNC specifications with precise shoulder dimensions (1/8" diameter, 7/8" length) controlled within tight tolerances. The fastener complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental compliance for industrial applications worldwide. Mechanical properties include Rockwell B55 hardness and 70,000 psi tensile strength, validated through quality control processes.