S-90298A596 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.
• Precise alignment and smooth rotation ensured by the 2-3/4" shoulder with tight diameter and length tolerances.
• High-strength, reliable fastening from Class 3A thread fit and Rockwell B55 hardness for demanding applications.
• Easy installation and removal with the hex socket drive and knurled head for improved grip.
• Wide compatibility with UNC coarse threads (1/4"-20) conforming to ASME B18.3 standards.
• Environmental and safety compliance meeting RoHS 3 and REACH regulations for global use.
• Durable, long-lasting performance in machinery and assemblies due to robust material and precise construction.

Professional Applications & Engineering Value

This 18-8 stainless steel shoulder screw is engineered to address critical alignment and wear issues in industrial machinery and precision equipment. The 2-3/4" shoulder length with minimal tolerances provides a stable bearing surface, reducing friction and preventing component misalignment. Its Class 3A thread fit and UNC coarse threads ensure secure, vibration-resistant fastening in high-stress environments. The passivated finish enhances corrosion resistance, extending service life in moist or chemical-exposed settings. Combined with a hex socket drive and knurled head, it simplifies maintenance and installation, making it a reliable choice for B2B procurement in automotive, aerospace, and manufacturing sectors.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for high precision, a shoulder diameter of 5/16" (tolerance: -0.001" to 0.001"), and shoulder length of 2-3/4" (tolerance: -0.005" to 0.005"). It complies with ASME B18.3 manufacturing standards and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring quality and safety in industrial applications.