S-91273A788 M4 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and black oxide finish, ideal for harsh industrial environments.
• Precise alignment and pivot support thanks to the 30mm shoulder with tight diameter tolerance (-0.04 to -0.01 mm), reducing assembly play.
• High mechanical strength offering 70,000 psi tensile and 35,000 psi minimum shear strength for reliable performance under load.
• Easy installation and removal with a 2 mm hex socket drive and knurled head for improved grip and torque application.
• Accurate and secure threading with Class 5g6g fit and M4 x 0.7mm coarse pitch, ensuring consistent fastening in various materials.
• Durable and wear-resistant due to Rockwell B55 hardness, maintaining integrity through repeated use.
• Compliance with global standards including RoHS 3 and REACH, ensuring safety and environmental responsibility.

Professional Applications & Engineering Value

This M4 shoulder screw is engineered to address critical alignment and wear challenges in precision assemblies. The 30mm shoulder length provides a stable unthreaded section that acts as a pivot, bearing surface, or locator, minimizing misalignment in machinery, automotive, and electronic enclosures. Made from 18-8 stainless steel with a black oxide finish, it resists corrosion and oxidation in humid or chemical-exposed settings. The hex socket drive and knurled head enhance torque transmission and reduce slippage during installation, while the Class 5g6g thread fit ensures reliable engagement in metric coarse pitch applications, reducing the risk of cross-threading and improving service life in high-vibration environments.

Specification Summary & Compliance

This shoulder screw adheres to metric system dimensions with a Class 5g6g thread fit for standard tolerance. The shoulder diameter is controlled to -0.04 to -0.01 mm, and shoulder length tolerance is 0 to 0.25 mm, ensuring precise assembly. It conforms to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing it is free from hazardous substances and suitable for international industrial use.