S-97768A377 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction and black oxide finish for prolonged service life in harsh environments
• Precise component alignment through the 1-3/4" shoulder length with tight diameter tolerance for reduced assembly vibration and wear
• Superior thread reliability with Class 3A UNC coarse threads ensuring consistent clamping force and vibration resistance
• Enhanced installation control via knurled socket head design providing secure grip and reduced tool slippage during torque application
• High mechanical strength delivering 70,000 psi tensile and 35,000 psi shear capacity for demanding pivot and machinery applications
• Industry-standard compliance with ASME B18.3 specifications guaranteeing dimensional accuracy and interchangeability
• Environmental regulation adherence through RoHS 3 and REACH compliance for global supply chain integration

Professional Applications & Engineering Value

This 18-8 stainless steel shoulder screw addresses critical alignment challenges in precision assemblies where rotational accuracy and component positioning are paramount. The black oxide finish enhances corrosion protection while maintaining dimensional stability, particularly valuable in automated machinery and pivot mechanisms exposed to operational stresses. Engineers specify this socket head shoulder screw for its Class 3A thread fit that prevents loosening under vibration, combined with the knurled head texture that enables positive drive engagement during installation. The 1/4"-20 UNC coarse thread configuration ensures rapid assembly in production environments, while the Rockwell B55 hardness provides optimal balance between machinability and wear resistance. These characteristics make it ideal for precision jigs, rotating assemblies, and bearing retention systems where dimensional accuracy directly impacts equipment performance and service intervals.

Specification Summary & Compliance

Manufactured to ASME B18.3 dimensional standards with Class 3A thread fit tolerance for precision assembly. The shoulder diameter maintains -0.004" to -0.002" tolerance with shoulder length held to -0.005" to 0.005" tolerance. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring unrestricted use in global industrial applications.