S-90298A617 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance thanks to 18-8 stainless steel construction and passivated finish, ensuring long-term reliability in harsh environments.
• Exceptional strength and durability with a tensile strength of 70,000 psi and Rockwell B55 hardness, providing reliable performance under high-stress conditions.
• Precise alignment and secure positioning due to the 3/8" shoulder diameter with a tight ±0.001" tolerance, minimizing assembly errors.
• Easy installation and removal with a hex socket drive and knurled head, offering improved grip and torque application without slipping.
• Reliable thread engagement from the 5/16"-18 UNC coarse thread with Class 3A fit, ensuring vibration resistance and secure fastening.
• Compliance with industry standards including ASME B18.3, RoHS, and REACH, guaranteeing quality and environmental safety for professional use.
• Versatile design with standard socket head profile and right-hand thread direction, making it suitable for a wide range of industrial applications.

Professional Applications & Engineering Value

This stainless steel shoulder screw is engineered to address common industrial challenges such as misalignment, corrosion, and mechanical failure. The 18-8 stainless steel material combined with a passivated finish provides excellent resistance to rust and chemicals, making it ideal for use in machinery, automotive assemblies, and electronic enclosures exposed to moisture or corrosive agents. The 3/8" shoulder diameter with minimal tolerance ensures precise component alignment, reducing wear and improving operational efficiency. With a coarse UNC thread and Class 3A fit, it offers quick assembly and high vibration resistance, while the hex drive and knurled head enhance usability in tight spaces. This screw delivers reliable performance in precision applications like pivots, bearings, and guides, where durability and accuracy are critical.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for precise thread engagement and a shoulder diameter tolerance of -0.001" to 0.001". It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances. Manufactured from 18-8 stainless steel with a passivated finish, it maintains consistent dimensions and performance in industrial settings.