S-90324A110 1/4"-20 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and long-term reliability.
• Exceptional mechanical strength offering 70,000 psi tensile strength and 35,000 psi minimum shear strength for heavy-duty applications.
• Precise Class 3A thread fit ensures secure, vibration-resistant fastening in left-hand thread assemblies.
• Knurled head design provides enhanced grip for manual adjustments and prevents slipping during installation.
• Accurate 1/2" shoulder length with tight tolerances for precise component alignment and spacing.
• Standard UNC coarse thread facilitates quick assembly and disassembly in industrial settings.
• Full regulatory compliance with RoHS 3 and REACH standards, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This 1/4"-20 left hand thread shoulder screw is engineered to address critical challenges in precision machinery and rotating assemblies. The 18-8 stainless steel material provides excellent corrosion resistance, reducing maintenance needs in humid or chemically aggressive environments. Its left-hand UNC thread is specifically designed for applications where reverse-threading prevents loosening under counter-clockwise rotation, such as in certain motors and conveyor systems. The knurled socket head allows for secure tool engagement and easy manual handling, while the precisely machined shoulder acts as a reliable bearing surface or pivot point, minimizing wear on connected components. This combination of high tensile strength and Class 3A thread fit ensures dependable performance in demanding industrial shoulder screw applications, from automation equipment to heavy machinery.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC left-hand thread with Class 3A fit for superior thread engagement. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 1/2" with a tolerance of -0.005" to 0.005", ensuring precise dimensional accuracy. Manufactured from 18-8 stainless steel with Rockwell B55 hardness, it complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental and safety standards are met for industrial use.