S-91273A581 1/4"-28 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel construction, ideal for harsh industrial environments.
• Enhanced durability and wear resistance from the Black Oxide finish, extending service life.
• High tensile strength of 70,000 psi ensures reliable performance under heavy loads.
• Precise thread engagement with Class 2A fit and UNF fine threads for secure, vibration-resistant assemblies.
• Easy installation and removal using the 1/8" hex socket drive and knurled head for improved grip.
• Rockwell B55 hardness provides excellent mechanical strength and resistance to deformation.
• Compliance with RoHS 3 and REACH ensures environmental safety and regulatory adherence.

Professional Applications & Engineering Value

This 18-8 Stainless Steel shoulder screw is engineered to address common industrial challenges such as corrosion, misalignment, and mechanical stress. The Black Oxide finish enhances surface protection, reducing oxidation in humid or chemical-exposed settings. With a 1/4"-28 UNF fine thread and Class 2A fit, it delivers precise alignment and secure fastening in machinery, automotive, and precision equipment applications. The hex socket head and knurled texture facilitate easy torque application, minimizing installation time and tool slippage. Its high tensile and shear strength ensures longevity in dynamic loads, making it a reliable choice for industrial fasteners requiring consistent performance.

Specification Summary & Compliance

This shoulder screw adheres to UNF thread standards with a Class 2A thread fit for dimensional accuracy. It meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance, ensuring it is free from hazardous substances. Specifications include a thread size of 1/4"-28, shoulder diameter tolerance of -0.004" to -0.002", and shoulder length tolerance of -0.005" to 0.005", supporting reliable integration in precision assemblies.