S-91829A511 4-40 MS51575-1, NASM51575 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 Stainless Steel and passivated finish, ideal for harsh industrial environments.
• Precise alignment and reduced wear due to the 1/8" diameter shoulder with tight tolerance control (-0.001" to 0").
• High mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for reliable, long-term performance.
• Easy installation and removal with a standard socket head and right-hand UNC coarse threads.
• Consistent thread quality ensured by Class 2A fit, providing secure fastening in precision assemblies.
• Compliance with strict standards including MS51575-1, RoHS 3, and REACH, ensuring safety and regulatory adherence.
• Versatile drive options with a slotted drive style for flexibility in various tooling applications.

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw is engineered to address critical alignment challenges in precision machinery, such as in aerospace, automotive, and electronics assembly. The 1/8" shoulder diameter with minimal tolerance variations ensures exact component positioning, reducing misalignment and vibration-induced failures. Made from 18-8 Stainless Steel with a passivated finish, it resists corrosion in moist or chemical-exposed settings, extending service life. The Class 2A thread fit and coarse UNC thread type facilitate quick assembly while maintaining high strength, making it ideal for applications demanding repeatable accuracy and durability under load.

Specification Summary & Compliance

This shoulder screw adheres to Class 2A thread fit and UNC thread standards for consistent dimensional accuracy. It meets MS51575-1 specifications and complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and material integrity. The shoulder features precise tolerances (diameter: -0.001" to 0"; length: 0" to 0.002") for reliable performance in industrial applications.