S-91273A321 M3 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction, ideal for harsh industrial environments and extended service life.
• Enhanced grip and torque application from the knurled socket head and 2mm hex drive, reducing tool slippage during installation.
• High mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness, ensuring reliable performance under load.
• Precision alignment and spacing enabled by the 5mm diameter shoulder, minimizing component misalignment in assemblies.
• Consistent and reliable thread engagement with Class 5g6g metric coarse thread (M3 x 0.5mm), facilitating quick assembly and disassembly.
• Compliance with environmental regulations, being RoHS 3 and REACH compliant, for use in regulated and international markets.
• Durable and wear-resistant design with precise shoulder diameter and length tolerances, maintaining fit and function over repeated use.

Professional Applications & Engineering Value

This M3 shoulder screw is engineered to address common industrial challenges such as component misalignment, corrosion-induced failure, and assembly inefficiency. Made from 18-8 stainless steel, it offers excellent resistance to rust and chemicals, making it suitable for applications in machinery, automotive, and electronics where exposure to moisture or contaminants is a concern. The knurled socket head with a 2mm hex drive ensures secure tool engagement, reducing the risk of stripping and improving installation speed. The 5mm shoulder diameter provides precise positioning for rotating parts like bearings or pulleys, while the Class 5g6g coarse thread allows for rapid fastening in high-vibration environments. This combination of corrosion-resistant material, high-strength design, and precision tolerances delivers long-term reliability and reduced maintenance in demanding industrial applications.

Specification Summary & Compliance

This shoulder screw features precise dimensional tolerances, including a shoulder diameter tolerance of -0.04 to -0.01 mm and shoulder length tolerance of 0 to 0.25 mm, ensuring consistent fit. The thread fit adheres to Class 5g6g standards for metric coarse threads (M3 x 0.5mm), providing reliable performance. It is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for environmentally conscious and global industrial use.