S-97345A620 1/4"-28 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh industrial and marine environments.
• Exceptional mechanical strength offering 70,000 psi tensile and 35,000 psi shear strength for reliable performance under high stress.
• Precise alignment and smooth rotation enabled by the 3" shoulder with tight diameter tolerance for accurate component positioning.
• Secure, non-slip fastening with a knurled socket head and hex drive, ensuring easy installation and removal without tool slippage.
• Fine thread (1/4"-28 UNF) with Class 3A fit provides superior vibration resistance and ensures a tight, secure connection in precision assemblies.
• Full compliance with ASME B18.3 standards, guaranteeing dimensional accuracy and interchangeability for engineering applications.
• Environmentally safe and regulated, meeting RoHS 3 and REACH compliance for use in global markets and sensitive industries.

Professional Applications & Engineering Value

This 316 Stainless Steel Shoulder Screw is engineered to address critical challenges in mechanical assemblies requiring precise alignment and durability. The 3" shoulder length acts as a pivot or axle, reducing wear on moving parts and maintaining exact spacing in machinery, robotics, and conveyor systems. Its fine UNF thread and Class 3A fit resist loosening under vibration, a common issue in automotive and aerospace applications. Made from corrosion-resistant 316 stainless steel, it performs reliably in aggressive environments like chemical processing or outdoor equipment, while the knurled socket head ensures secure tool engagement for efficient maintenance. Ideal for high-tensile industrial fasteners, it combines strength with precision to extend equipment lifespan and reduce downtime.

Specification Summary & Compliance

This shoulder screw features a 1/4"-28 UNF fine thread with Class 3A fit for tight tolerances, a shoulder diameter of 3/8" with tolerance of -0.004" to -0.002", and a shoulder length of 3" with tolerance of -0.005" to 0.005". It is manufactured to ASME B18.3 specifications and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and industry-standard reliability.