S-94328A974 5/16"-18 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Capacity: With a tensile strength of 140,000 psi, this shoulder screw reliably handles high-stress applications, reducing the risk of fastener failure in demanding environments.
• Superior Wear and Corrosion Resistance: The black oxide finish on alloy steel provides enhanced durability and protection against rust, extending the screw's service life in various industrial conditions.
• Precision Thread Fit for Secure Assembly: The Class 3A thread fit ensures tight, precise engagement with mating parts, minimizing backlash and improving overall assembly stability.
• Easy Installation and Removal: The hex drive (3/16") and knurled, low-profile socket head allow for efficient tool access and torque application, even in confined spaces, speeding up maintenance and assembly processes.
• Accurate Shoulder Positioning: Features a controlled shoulder diameter and length with tight tolerances, providing consistent alignment and spacing for components like gears and pulleys.
• Compliance with Environmental and Safety Standards: Meets RoHS 3 and REACH regulations, ensuring the screw is free from hazardous substances and suitable for global supply chains.
• Optimized for High-Strength Applications: The combination of Rockwell C30 hardness and UNC coarse threads offers excellent resistance to stripping and wear, ideal for repetitive disassembly and heavy-duty use.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address common challenges in precision mechanical assemblies, such as misalignment and component wear. The black oxide finish not only enhances corrosion resistance but also reduces galling during installation, which is critical in high-cycle applications. With a 5/16"-18 UNC coarse thread and Class 3A fit, it ensures rapid, secure fastening in industrial equipment, robotics, and automotive systems, where vibration resistance and repeatability are paramount. The low-profile socket head with knurling improves grip and tool engagement, minimizing slippage and damage in tight spaces. By providing a reliable shoulder for bearing surfaces, this screw helps maintain precise axial positioning, reducing maintenance downtime and improving the longevity of assembled components.

Specification Summary & Compliance

This shoulder screw adheres to UNC thread standards with a Class 3A thread fit for high precision. Dimensions include a thread diameter of 0.313", thread length of 1/2", shoulder diameter of 3/8" (tolerance: -0.004" to -0.002"), and shoulder length of 1" (tolerance: -0.005" to 0.005"). It is manufactured from alloy steel with a hardness of Rockwell C30 and tensile strength of 140,000 psi. The product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), ensuring it meets environmental and safety regulations for industrial use.