S-8077A786 3/8"-16 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.
• Exceptional mechanical strength delivering 70,000 psi tensile and 35,000 psi shear strength for reliable performance under high stress.
• Precise thread engagement with Class 3A UNC coarse threads ensuring secure, vibration-resistant fastening in industrial assemblies.
• Enhanced durability and wear resistance from the black oxide finish, which also reduces light reflection and provides a sleek appearance.
• Easy installation and removal using a standard 5/16" hex drive and knurled head for improved grip during manual or tool-assisted handling.
• Accurate shoulder positioning with controlled diameter and length tolerances for consistent alignment in machinery and rotating components.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery, automation systems, and heavy-duty equipment. The 3/8"-16 UNC Class 3A thread with coarse spacing provides rapid assembly and high resistance to loosening under dynamic loads, while the black oxide finish enhances corrosion protection without compromising dimensional integrity. The knurled socket head and hex drive enable quick tool engagement, reducing installation time in confined spaces. Ideal for applications requiring a sturdy shoulder to maintain component alignment—such as in bearings, pulleys, and linkages—this screw’s 70,000 psi tensile strength and Rockwell B79 hardness ensure long-term reliability in demanding industrial settings, from food processing to chemical handling.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit and UNC coarse thread standards for precise engagement. Manufacturing conforms to ASME B18.3 specifications, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of -0.005" to 0.005" ensuring consistent performance. The product is fully RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliant, meeting stringent environmental and safety regulations for industrial use.