S-90298A575 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel and passivated finish, ideal for harsh industrial environments.
• Exceptional strength and durability from 70,000 psi tensile strength and Rockwell B55 hardness, ensuring reliable performance under high stress.
• Precise alignment and smooth rotation with a 5/16" shoulder diameter held to tight tolerances (±0.001"), reducing wear in assemblies.
• Secure, high-precision threading via Class 3A UNC 1/4"-20 coarse threads, offering excellent fit and vibration resistance.
• Easy installation and removal with a hex socket drive (5/32") and knurled head, providing a firm grip and reducing tool slippage.
• Broad industrial compliance meeting ASME B18.3, RoHS 3, and REACH standards, ensuring safety and regulatory acceptance.
• Versatile right-hand coarse threading for quick assembly in various machinery and equipment applications.

Professional Applications & Engineering Value

This stainless steel shoulder screw is engineered to address critical alignment and durability challenges in precision assemblies. The 18-8 stainless steel material combined with a passivated finish provides excellent resistance to corrosion and oxidation, making it suitable for environments exposed to moisture or chemicals. The 5/16" shoulder diameter with minimal tolerance ensures precise component positioning, reducing misalignment and extending the life of moving parts in machinery, automotive, and electronic equipment. Its Class 3A UNC 1/4"-20 thread and coarse pitch enable secure fastening with high vibration resistance, while the hex socket drive and knurled head facilitate easy handling in tight spaces. Ideal for use in industrial fasteners requiring reliable strength and compliance, this screw minimizes maintenance and enhances operational efficiency.

Specification Summary & Compliance

This shoulder screw adheres to tight dimensional tolerances, including a shoulder diameter tolerance of -0.001" to 0.001" and shoulder length tolerance of -0.005" to 0.005", ensuring precision in Class 3A thread fit and UNC coarse threading. It meets ASME B18.3 specifications for consistent quality and performance. Additionally, the product is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and suitable for global industrial applications.