S-90278A321 M4 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh environments and extended service life.
• Precise component alignment ensured by the 5mm shoulder with tight diameter and length tolerances for reduced assembly vibration.
• High-strength performance offering 70,000 psi tensile strength and Rockwell B55 hardness for demanding mechanical applications.
• Secure, reliable fastening with a Class 6g thread fit and coarse M4 x 0.7mm thread for quick assembly and strong hold.
• Easy installation and removal using a standard 2.5 mm hex key in the socket head, preventing tool slippage and damage.
• Environmental compliance assurance meeting RoHS 3 and REACH standards for safe use in regulated industries.
• Versatile metric sizing with right-hand coarse threads compatible with standard metric components and tooling.

Professional Applications & Engineering Value

This M4 shoulder screw is engineered to address critical alignment and durability challenges in precision assemblies. The 18-8 stainless steel material provides excellent resistance to rust and corrosion, making it suitable for applications in electronics, automotive, and machinery exposed to moisture or chemicals. The 5mm shoulder length with precise tolerances acts as a dependable pivot or spacer, minimizing misalignment and wear in rotating parts like gears, pulleys, and linkages. The socket head hex drive allows for high-torque installation in confined spaces, while the Class 6g thread fit ensures consistent engagement without cross-threading. By integrating these features, this shoulder screw enhances assembly accuracy, reduces maintenance needs, and supports long-term operational reliability in industrial fastening systems.

Specification Summary & Compliance

This precision shoulder screw adheres to metric system standards with an M4 x 0.7mm coarse thread and Class 6g thread fit for consistent performance. The shoulder diameter tolerance is -0.025 to 0 mm, and shoulder length tolerance is 0 to 0.05 mm, ensuring exact fit in precision applications. It is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in environmentally conscious and regulated industries.