S-90298A607 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 extended service life.
• Exceptional alignment precision due to the 5" shoulder length with tight tolerances (±0.005"), ensuring accurate component positioning.
• High-strength performance with a tensile strength of 70,000 psi and a minimum shear strength of 35,000 psi for demanding applications.
• Secure and reliable thread engagement provided by the Class 3A UNC coarse thread fit, reducing the risk of loosening under vibration.
• Enhanced grip and easy installation from the knurled socket head and 5/32" hex drive, allowing for efficient assembly even in confined spaces.
• Consistent durability backed by Rockwell B55 hardness, maintaining structural integrity under repeated use.
• Regulatory compliance and quality assurance meeting ASME B18.3, RoHS 3, and REACH standards for safe and reliable industrial use.

Professional Applications & Engineering Value

This shoulder screw is engineered to solve critical alignment and durability challenges in industrial settings. The 18-8 Stainless Steel material offers excellent corrosion resistance, making it suitable for machinery exposed to moisture or chemicals. Its 5" shoulder length with precise tolerances ensures exact component alignment, reducing wear and misalignment in assemblies like pivots, gears, and linkages. The Class 3A UNC thread with coarse spacing provides robust fastening, ideal for high-vibration environments. Combined with a knurled socket head for secure handling and a hex drive for easy installation, this screw enhances efficiency in manufacturing, automation, and heavy equipment applications, delivering long-term reliability and reduced maintenance costs.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit and UNC thread standards, ensuring precise dimensional accuracy. Manufacturing follows ASME B18.3 specifications, with shoulder diameter tolerance of -0.004" to -0.002" and shoulder length tolerance of ±0.005". It is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental safety and material integrity for industrial use.