S-94383A310 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength for reliable performance in high-stress applications.
• Superior corrosion resistance from the black oxide finish, extending service life in demanding industrial environments.
• Precise thread engagement with Class 3A fit and UNC coarse threads, ensuring secure fastening and vibration resistance.
• Enhanced grip and torque application due to the knurled socket head and hex drive, allowing for easy installation and removal.
• High durability and wear resistance from alloy steel construction and Rockwell C32 hardness, minimizing deformation under repeated use.
• Accurate shoulder dimensions with tight tolerances for consistent alignment in assemblies, reducing installation errors.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in industrial machinery, automation, and precision equipment. The black oxide finish provides a protective layer against rust and corrosion, making it ideal for environments exposed to moisture or chemicals. With a Class 3A thread fit and UNC coarse threads, it offers reliable fastening in applications requiring high vibration resistance, such as rotating shafts or linkages. The knurled socket head and hex drive design enable efficient torque transfer, reducing the risk of stripping during assembly. Its robust 140,000 psi tensile strength and precise shoulder dimensions ensure stable alignment in jigs, fixtures, and bearing mounts, minimizing downtime and maintenance costs. Suitable for use in automotive, aerospace, and manufacturing sectors, this screw delivers long-term performance where precision and durability are paramount.

Specification Summary & Compliance

This shoulder screw features a 5/16"-18 UNC thread with Class 3A fit for tight tolerances and secure engagement. Dimensions include a shoulder diameter of 3/8" with a tolerance of -0.004" to -0.002" and shoulder length of 1/4" with a tolerance of -0.005" to 0.005", ensuring precise assembly. It meets ASME B18.3 specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting environmental and safety standards in industrial applications.