S-90311A187 3/8"-16 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 316 stainless steel construction, ideal for harsh environments and extended service life.
• Enhanced joint integrity through a permanent nylon patch thread locker that prevents loosening under vibration from -50° to 250°F.
• High load-bearing capacity with 70,000 psi tensile strength and 35,000 psi shear strength for reliable performance in demanding applications.
• Precise alignment and smooth rotation enabled by the 2" shoulder with tight diameter tolerance, reducing wear on mating parts.
• Secure and efficient installation using the hex socket drive and knurled head for superior grip and torque application.
• Consistent fit and interchangeability thanks to Class 3A thread fit and UNC coarse threading, ensuring easy assembly.
• Compliance with industry standards including ASME B18.3, RoHS, and REACH, guaranteeing quality and environmental safety.

Professional Applications & Engineering Value

This 3/8"-16 UNC shoulder screw is engineered to address critical challenges in precision machinery and industrial assemblies. The 316 stainless steel material provides excellent resistance to corrosion and chemicals, making it suitable for marine, chemical processing, and food-grade equipment. Its 2" shoulder length and controlled diameter tolerance ensure accurate pivoting and alignment in rotating mechanisms, such as linkages and bearings, minimizing friction and component wear. The integrated nylon patch thread locker offers a permanent locking feature that maintains clamp load under high-vibration conditions, eliminating the need for secondary locking devices. With a hex socket head and knurled texture, it allows for high-torque installation in confined spaces, enhancing assembly efficiency and reliability in automated systems and heavy-duty fixtures.

Specification Summary & Compliance

This shoulder screw features a Class 3A thread fit with UNC coarse threading (3/8"-16) for precise engagement and a shoulder diameter of 1/2" with a tolerance of -0.004" to -0.002". The shoulder length is 2" with a tolerance of -0.005" to 0.005", ensuring dimensional accuracy. It is manufactured in compliance with ASME B18.3 standards and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, confirming its suitability for global industrial use without hazardous substances.