S-97768A332 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel and black oxide finish, ideal for harsh industrial environments
• Precise alignment and secure positioning thanks to the 2-3/4" shoulder length with tight tolerances for consistent performance
• High tensile strength of 70,000 psi and Rockwell B55 hardness for reliable load-bearing in demanding applications
• Easy installation and removal with hex drive socket head and knurled texture for improved grip
• Accurate thread engagement with Class 3A UNC coarse threads ensuring secure fastening and vibration resistance
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH for quality assurance and environmental safety
• Durable construction with a minimum shear strength of 35,000 psi for long-term reliability in mechanical assemblies

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical alignment and durability challenges in industrial settings. The 18-8 stainless steel material, combined with a black oxide finish, provides excellent resistance to corrosion and wear, making it suitable for machinery, automotive, and aerospace applications where exposure to moisture and chemicals is common. The 2-3/4" shoulder length with precise tolerances ensures accurate component positioning, reducing misalignment and wear in rotating assemblies. With a Class 3A UNC thread and hex drive socket head, it offers quick, secure installation, minimizing downtime in production lines. Its high tensile strength and Rockwell B55 hardness support heavy-duty use, delivering consistent performance in pivots, guides, and other precision mechanisms.

Specification Summary & Compliance

This shoulder screw features a 1/4"-20 UNC thread with Class 3A fit for high precision and reliability. The shoulder diameter is 5/16" with a tolerance of -0.004" to -0.002", and the shoulder length is 2-3/4" with a tolerance of -0.005" to 0.005", ensuring consistent dimensional accuracy. It complies with ASME B18.3 specifications for manufacturing standards, and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) requirements for environmental and safety regulations.