S-97345A809 1/2"-13 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh chemical and marine environments.
• High mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable load-bearing in demanding applications.
• Precise Class 3A thread fit ensures tight tolerances and secure fastening, reducing the risk of loosening under vibration.
• Knurled socket head with 5/16" hex drive provides excellent grip and torque transmission during installation, minimizing tool slippage.
• Durable shoulder design with 5/8" diameter and 2 1/8" length acts as a precise pivot, spacer, or bearing surface in assemblies.
• Compliance with ASME B18.3 standards guarantees consistent quality and interchangeability in industrial applications.
• Environmentally safe with RoHS 3 and REACH compliance, meeting global regulatory requirements for hazardous substances.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in machinery, automation, and structural assemblies where corrosion resistance and precision alignment are paramount. The 1/2"-13 UNC coarse thread with Class 3A fit ensures rapid assembly and high clamping force, reducing installation time while maintaining integrity under dynamic loads. The knurled socket head enhances tool engagement, preventing stripping in high-torque scenarios. Its shoulder serves as an accurate locating feature for rotating components or as a wear-resistant journal, minimizing maintenance in conveyor systems, pivoting mechanisms, and precision instruments. By combining high tensile strength with excellent durability, this fastener extends service life in demanding industrial environments, from chemical processing to marine equipment.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with Class 3A thread fit for precise engagement and UNC coarse threads for efficient assembly. Key dimensions include a shoulder diameter of 5/8" (tolerance: -0.004" to -0.002") and shoulder length of 2 1/8" (tolerance: -0.005" to 0.005"), ensuring consistent performance. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, confirming it is free from restricted hazardous substances, and is manufactured from 316 stainless steel with a hardness of Rockwell B79 for reliable mechanical properties.