S-97768A388 5/16"-24 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments
• Superior load-bearing capacity with 70,000 psi tensile strength and 35,000 psi minimum shear strength for demanding applications
• Precise alignment and reduced wear thanks to Class 3A thread fit and tight shoulder diameter tolerance (-0.004" to -0.002")
• Enhanced grip and tool engagement from the knurled socket head and hex drive, preventing slippage during installation
• Improved durability and reduced galling with black oxide finish on stainless steel, extending service life
• Reliable performance in regulated industries with compliance to ASME B18.3, RoHS 3, and REACH standards
• Accurate positioning enabled by the 2-1/2" shoulder length with minimal tolerance variation

Professional Applications & Engineering Value

This 5/16"-24 UNF shoulder screw is engineered to address critical alignment and mechanical stress challenges in precision machinery, automation systems, and rotating assemblies. The 18-8 stainless steel material combined with a black oxide finish provides excellent resistance to corrosion and wear, reducing maintenance in humid or chemically exposed settings. The Class 3A thread fit and fine thread spacing ensure secure fastening with minimal vibration loosening, while the knurled socket head allows for high-torque installation without stripping. Ideal for use in industrial fastening applications such as pivots, guides, and spindles, this shoulder screw maintains dimensional stability under loads up to 70,000 psi tensile strength, offering long-term reliability and reduced downtime.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNF fine threads (5/16"-24) and a thread length of 3/8". Shoulder dimensions include a diameter of 3/8" with tolerance of -0.004" to -0.002" and length of 2-1/2" with tolerance of -0.005" to 0.005". It conforms to ASME B18.3 specifications and is RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, ensuring adherence to international safety and environmental standards.