S-97345A589 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 environments and chemical exposure.
• Exceptional mechanical strength offering 70,000 psi tensile strength and 35,000 psi minimum shear strength for reliable performance under high-stress loads.
• Precision Class 3A thread fit ensures tight, secure fastening with minimal backlash in high-precision assemblies.
• Enhanced torque transmission via the knurled socket head and 3/16" hex drive, preventing tool slippage and improving installation efficiency.
• Accurate alignment and spacing provided by the precisely machined shoulder with controlled diameter and length tolerances.
• Broad regulatory compliance including ASME B18.3 standards, RoHS 3, and REACH, ensuring safety and environmental responsibility.
• Optimized for fine-thread applications with 1/4"-28 UNF threads, offering superior vibration resistance and clamping force.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision machinery, automation systems, and rotating assemblies. The Class 3A thread fit and UNF fine thread design provide exceptional resistance to loosening under vibration, a common failure point in dynamic equipment. The knurled socket head with a 3/16" hex drive ensures maximum torque application without cam-out, reducing assembly time and tool wear. Its corrosion-resistant material makes it suitable for medical devices, food processing, and marine applications where hygiene and durability are paramount. The precisely controlled shoulder diameter and length act as a pivot or spacer, maintaining alignment in bearings, gears, and linkages, thereby reducing wear and extending component life.

Specification Summary & Compliance

This shoulder screw features a 1/4"-28 UNF fine thread with a precision Class 3A thread fit for secure fastening. The shoulder is manufactured to tight tolerances: diameter of 3/8" (-0.004" to -0.002") and length of 1/2" (-0.005" to 0.005"). It complies with ASME B18.3 specifications for dimensional accuracy and performance. The product is also RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting stringent environmental and safety regulations for hazardous substances.