S-97768A347 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments
• Superior thread engagement and vibration resistance due to UNC coarse threading with precise Class 3A fit
• Enhanced tool grip and reduced slippage from the knurled head texture combined with 3/16" hex drive
• High mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for demanding applications
• Improved wear resistance and reduced light reflection with black oxide finish
• Accurate component alignment ensured by the 3/8" shoulder diameter with tight tolerance control
• Full regulatory compliance meeting ASME B18.3, RoHS 3, and REACH for safe, reliable use

Professional Applications & Engineering Value

This 18-8 stainless steel shoulder screw is engineered to address critical challenges in precision assembly and rotating machinery. The black oxide finish not only enhances corrosion resistance but also minimizes galling in high-friction applications. With its UNC coarse thread and Class 3A fit, it ensures rapid installation and maintains clamp load under vibration, making it ideal for automotive fixtures, conveyor systems, and robotic arms. The knurled head texture provides secure tool engagement, reducing the risk of stripping during torque application. Its 3/8" shoulder diameter acts as a precise pivot or spacer, eliminating misalignment in linkages and bearings while supporting substantial shear loads up to 35,000 psi.

Specification Summary & Compliance

The screw features a 1/4"-20 UNC thread with Class 3A fit for high precision, a shoulder diameter of 3/8" (tolerance: -0.004" to -0.002"), and shoulder length of 1/4" (tolerance: -0.005" to 0.005"). It is manufactured in compliance with ASME B18.3 standards and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safety and reliability for industrial use.