S-90298A649 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments.
• Enhanced installation grip from the knurled socket head, preventing tool slippage during high-torque applications.
• Precise component alignment enabled by the long 6-1/2" shoulder with tight diameter tolerance.
• High load-bearing capacity with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding mechanical uses.
• Reliable thread engagement due to Class 3A thread fit and coarse UNC thread for quick assembly and vibration resistance.
• Durable mechanical performance ensured by Rockwell B55 hardness, maintaining integrity under repeated stress.
• Secure drive compatibility with the 3/16" hex drive, offering common tool fit and consistent fastening.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and durability challenges in industrial machinery, automated systems, and precision equipment. The 18-8 stainless steel material provides excellent resistance to rust and corrosion, extending service life in moist or chemically exposed settings. The 6-1/2" shoulder length and precise shoulder diameter allow for accurate positioning of moving parts like gears, pulleys, and linkages, reducing wear and minimizing maintenance. Combined with the coarse UNC thread and Class 3A thread fit, it ensures secure fastening even in high-vibration environments, while the knurled socket head enhances torque application for reliable installation. Ideal for applications requiring robust shoulder bolts that maintain dimensional stability under heavy loads.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for superior thread engagement and a shoulder diameter tolerance of -0.004" to -0.002". It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental compliance standards, ensuring safety and sustainability. The UNC coarse thread and right-hand thread direction provide efficient assembly, backed by a tensile strength of 70,000 psi and hardness of Rockwell B55 for consistent performance in industrial applications.