S-97832A291 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and reducing maintenance costs.
• Exceptional strength and durability with a tensile strength of 70,000 psi and Rockwell B55 hardness for reliable performance under high stress.
• Precise alignment and smooth rotation ensured by the 3" shoulder with tight diameter and length tolerances for consistent assembly.
• High-torque installation capability from the knurled socket head and 3/16" hex drive, preventing tool slippage and improving efficiency.
• Secure, vibration-resistant fastening with Class 3A thread fit and 1/4"-20 UNC coarse thread, minimizing loosening in dynamic applications.
• Broad industry compliance meeting ASME B18.3, RoHS 3, and REACH standards, ensuring safety and environmental responsibility.
• Optimized for repetitive use with a minimum shear strength of 35,000 psi, extending service life in demanding machinery.

Professional Applications & Engineering Value

This precision shoulder screw is engineered to address critical alignment and wear challenges in industrial machinery. The 18-8 stainless steel material offers excellent corrosion resistance, reducing downtime in moist or chemical-exposed settings. Its 3" shoulder length and controlled tolerances provide a stable pivot or bearing surface, preventing misalignment in assemblies like rotating shafts, linkages, and guides. The knurled socket head and 3/16" hex drive ensure maximum torque transfer during installation, which is vital for high-vibration environments. With a Class 3A thread fit and UNC coarse thread, it delivers reliable clamping force in automated equipment, packaging systems, and precision instruments, enhancing operational reliability and reducing maintenance intervals.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC coarse thread with Class 3A thread fit for precise engagement. The shoulder diameter is 3/8" with a tolerance of -0.004" to -0.002", and the shoulder length is 3" with a tolerance of -0.005" to 0.005", ensuring dimensional accuracy. It complies with ASME B18.3 manufacturing specifications and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, confirming its suitability for global industrial use.