S-90311A162 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Vibration-resistant locking with permanent nylon patch thread locker that maintains secure fastening from -50° to 250°F, preventing loosening in demanding environments
• Superior corrosion resistance through 316 stainless steel construction, ideal for harsh chemical or marine applications
• Precise component alignment with standard shoulder fit and controlled diameter tolerances (-0.004" to -0.002") for accurate positioning
• High-strength performance delivering 70,000 psi tensile strength and 35,000 psi shear strength for heavy-duty industrial applications
• Easy installation and removal with 5/32" hex socket drive and knurled head for improved grip during torque application
• Reliable thread engagement through Class 3A UNC coarse threads ensuring consistent mating with components
• Industry compliance assurance meeting ASME B18.3 specifications while being RoHS 3 and REACH compliant

Professional Applications & Engineering Value

Engineered for precision machinery and industrial equipment, this 1/4"-20 UNC shoulder screw solves critical alignment and vibration challenges in rotating assemblies, pivoting mechanisms, and precision guides. The 316 stainless steel construction provides exceptional resistance to corrosive environments while the nylon patch thread locker eliminates maintenance-intensive retightening in high-vibration applications. The combination of Class 3A thread fit and controlled shoulder diameter tolerance (-0.004" to -0.002") ensures precise component positioning in automated systems, conveyor equipment, and manufacturing fixtures. The socket head design with 5/32" hex drive facilitates installation in confined spaces while the knurled head enhances grip during assembly operations.

Specification Summary & Compliance

This shoulder screw features 1/4"-20 UNC Class 3A threads with coarse thread spacing and right-hand direction. The shoulder diameter maintains -0.004" to -0.002" tolerance with shoulder length tolerance of -0.005" to 0.005". Manufactured to ASME B18.3 specifications with Rockwell B79 hardness. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards for industrial use.