S-97345A693 5/16"-18 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh industrial environments and chemical exposure.
• Exceptional mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable, high-stress load-bearing applications.
• Precise component alignment enabled by the 4" shoulder with tight tolerances, reducing wear and ensuring smooth rotational movement.
• Secure, non-slip installation thanks to the knurled socket head and hex drive, allowing for high-torque application without tool slippage.
• Durable, coarse UNC threading (Class 3A fit) for faster assembly and superior vibration resistance in demanding machinery.
• Broad regulatory compliance including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental standards are met for global supply chains.
• Optimized for industrial use with a Rockwell B79 hardness, balancing toughness and machinability for long service life.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision assembly and rotating machinery. The 4" shoulder length with minimal diameter tolerance provides an exact pivot or bearing surface, eliminating misalignment and reducing friction in applications like conveyor systems, robotic arms, and printing equipment. The coarse 5/16"-18 UNC thread (Class 3A) ensures rapid, secure fastening even in high-vibration environments, while the knurled socket head with hex drive allows for high torque application without cam-out. Made from corrosion-resistant 316 stainless steel, it withstands aggressive conditions—including moisture, chemicals, and salt spray—making it a reliable choice for food processing, marine, and pharmaceutical industries where hygiene and durability are paramount.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for precise, secure fastening. The shoulder diameter tolerance is -0.004" to -0.002", and shoulder length tolerance is -0.005" to 0.005", ensuring consistent dimensional accuracy. It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally sensitive and regulated industrial markets.