S-91327A132 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Permanent vibration resistance with nylon patch thread locker that maintains secure fastening in dynamic applications
• Superior corrosion protection through 18-8 stainless steel construction and passivated surface treatment
• High-strength performance with 70,000 psi tensile strength for demanding industrial applications
• Precision installation control featuring knurled socket head and 5/32" hex drive for non-slip torque application
• Exceptional thread accuracy with Class 3A fit ensuring reliable engagement and consistent clamping force
• Wide temperature tolerance from -50° to 250°F for stable performance in varied operating environments
• Regulatory compliance assurance meeting ASME B18.3 standards and environmental regulations including RoHS 3 and REACH

Professional Applications & Engineering Value

This 1/4"-20 UNC shoulder screw delivers critical engineering solutions for precision assemblies requiring both structural integrity and vibration resistance. The 18-8 stainless steel construction with passivated finish provides exceptional corrosion resistance in harsh environments, while the permanent nylon patch thread locker eliminates the need for secondary locking components in rotating machinery and vibrating equipment. The knurled socket head design ensures positive drive engagement during installation, preventing tool slippage that can damage critical components. With its Class 3A thread fit and precisely machined shoulder, this fastener maintains alignment in pivot points, bearing assemblies, and precision mechanisms where dimensional stability is paramount. The combination of 70,000 psi tensile strength and temperature stability from -50° to 250°F makes it ideal for automotive, aerospace, and industrial machinery applications where reliability cannot be compromised.

Specification Summary & Compliance

This shoulder screw features precision UNC coarse threads with Class 3A fit for superior thread engagement and consistent performance. Manufactured to ASME B18.3 specifications with critical dimensions including 1/4"-20 thread size, 7/16" thread length, and 5/16" shoulder diameter with tight tolerances. The fastener is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. The nylon patch thread locking system provides permanent vibration resistance without compromising the material integrity of the 18-8 stainless steel base material.