S-90298A738 3/8"-16 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ensuring long-term reliability in harsh environments
• Precise component alignment through Class 3A thread fit and tight shoulder diameter tolerance (±0.001"), reducing assembly errors
• Enhanced torque transmission with hex socket drive and knurled head design, preventing tool slippage during installation
• Exceptional mechanical strength from Rockwell B55 hardness, maintaining structural integrity under heavy loads
• Optimized for industrial applications with coarse UNC threading and 4 1/4" shoulder length, providing stable rotational support
• Compliance with global standards including ASME B18.3, RoHS 3, and REACH, ensuring regulatory acceptance
• Right-hand threading compatibility with standard UNC 3/8"-16 specifications, facilitating easy integration

Professional Applications & Engineering Value

This 3/8"-16 UNC shoulder screw delivers critical engineering solutions where precision alignment and rotational stability are paramount. The 18-8 stainless steel material combined with passivated finish provides exceptional corrosion resistance, making it ideal for machinery, automation systems, and outdoor equipment exposed to moisture or chemicals. The 4 1/4" shoulder length and 1/2" shoulder diameter create a precise bearing surface that prevents lateral movement in pulleys, gears, and linkages. With Class 3A thread fit and hex socket head design, it ensures secure fastening in high-vibration environments while the knurled texture enhances grip during manual adjustments. These features collectively address common industrial challenges of misalignment, component wear, and maintenance downtime.

Specification Summary & Compliance

This shoulder screw maintains Class 3A thread fit per UNC standards with ±0.001" shoulder diameter tolerance and ±0.005" shoulder length tolerance. Manufactured in compliance with ASME B18.3 specifications and certified RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant. The Rockwell B55 hardness ensures mechanical durability while the right-hand UNC 3/8"-16 coarse threading provides reliable engagement in industrial assemblies.