S-97345A521 1/4"-28 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel material, ideal for harsh industrial environments and extended service life.
• High-strength performance offering 70,000 psi tensile and 35,000 psi shear strength for reliable load-bearing in demanding applications.
• Precise alignment and smooth rotation ensured by the 1" shoulder with tight diameter and length tolerances, reducing wear and misalignment.
• Fine UNF thread with Class 3A fit provides excellent vibration resistance and secure fastening in high-precision assemblies.
• Easy installation and removal with a hex socket drive (5/32") and knurled head for improved grip and torque application.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility.
• Durable construction with Rockwell B79 hardness for enhanced wear resistance and long-term reliability in mechanical systems.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery, such as maintaining alignment in rotating assemblies and reducing friction in pivot points. The 1/4"-28 UNF fine thread and Class 3A fit ensure minimal backlash and superior vibration resistance, making it ideal for applications in aerospace, automotive, and industrial equipment. The knurled socket head allows for secure tool engagement, while the precise shoulder diameter and length facilitate accurate component positioning. By using high-tensile strength materials and compliant finishes, this screw minimizes downtime and maintenance costs in corrosive or high-stress environments, delivering consistent performance and engineering reliability.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 specifications, with a Class 3A thread fit for tight tolerances and a shoulder diameter tolerance of -0.004" to -0.002" and length tolerance of -0.005" to 0.005". It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances and suitable for global industrial use. The UNF fine thread and precise shoulder dimensions support high-accuracy applications, backed by material certifications for reliability and safety.