S-97768A326 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability: 18-8 Stainless Steel construction with Black Oxide finish provides excellent corrosion resistance, extending service life in harsh industrial environments.
• Superior Load-Bearing Capacity: High tensile strength of 70,000 psi and minimum shear strength of 35,000 psi ensure reliable performance under heavy mechanical stress.
• Precision Alignment & Smooth Rotation: The 2" shoulder length with controlled tolerances acts as a precise pivot or bearing surface, reducing wear in assemblies.
• Secure, Non-Slip Installation: Knurled socket head with 5/32" hex drive prevents tool slippage, allowing for high torque application and consistent clamping force.
• Reliable Thread Engagement: Class 3A thread fit and 1/4"-20 UNC coarse threads offer superior vibration resistance and faster assembly in demanding applications.
• Industry Compliance & Safety: Meets ASME B18.3 specifications and is RoHS 3/REACH compliant, ensuring material safety and regulatory adherence for global supply chains.
• Optimized for High-Stress Applications: Rockwell B55 hardness provides a balance of strength and ductility, preventing brittleness and failure in dynamic loads.

Professional Applications & Engineering Value

This black oxide stainless steel shoulder screw is engineered to address critical alignment and load distribution challenges in industrial machinery, automation systems, and precision equipment. The 2" shoulder length serves as an integral bearing surface, minimizing friction and maintaining component positioning in rotating assemblies like pivots, gears, and linkages. Made from 18-8 Stainless Steel, it resists oxidation and chemical exposure, while the Class 3A thread fit and coarse UNC threads ensure secure fastening even under vibration. The knurled socket head enhances grip during installation, reducing the risk of stripping and improving maintenance efficiency. Ideal for applications requiring high tensile and shear strength, this screw provides long-term reliability in manufacturing, automotive, and aerospace sectors where precision and durability are paramount.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 standards, with a Class 3A thread fit for precise thread engagement and a shoulder diameter tolerance of -0.004" to -0.002" for accurate alignment. It is manufactured from 18-8 Stainless Steel with a Black Oxide finish and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring environmental safety and material integrity. The screw features a 1/4"-20 UNC coarse thread and a 2" shoulder length with a tolerance of -0.005" to 0.005", supporting consistent performance in regulated industrial applications.