S-91190A520 4.4 mm ID x 7 mm OD DIN 7980 Split Lock Washers for Socket Head Screws

Key Features & Benefits at a Glance

• Superior vibration resistance ensures fasteners stay securely locked even under intense dynamic loads and machinery operation.
• Enhanced corrosion protection from the black-oxide steel finish prolongs service life in harsh or humid industrial environments.
• Reliable, consistent performance guaranteed by the high Rockwell C44 hardness, providing excellent spring-back and load distribution.
• Precise metric fit for M4 screws with a 4.4mm ID and 7mm OD ensures easy installation and optimal force application.
• Compliance with DIN 7980 standard assures dimensional accuracy, interchangeability, and quality for European engineering projects.
• Environmentally responsible manufacturing with full RoHS 3 and REACH compliance, meeting strict global regulatory requirements.
• Durable 1.1-1.3mm thickness offers the ideal balance of flexibility and strength for repeated use without failure.

Professional Applications & Engineering Value

This M4 split lock washer is engineered to solve critical loosening issues in industrial applications where vibration and thermal cycling are common. Made from black-oxide steel, it provides a protective barrier against rust and oxidation, making it suitable for automotive assemblies, machinery, and electrical enclosures exposed to moisture. The standard split lock design and precise metric dimensions create a continuous spring force that maintains clamp load, preventing back-off and reducing maintenance downtime. Its DIN 7980 conformity ensures it meets rigorous German engineering standards, offering reliability in high-stress environments like motor mounts, conveyor systems, and heavy equipment where vibration resistance is non-negotiable.

Specification Summary & Compliance

This washer conforms to DIN 7980 for dimensional precision and thread fit. It is manufactured from black-oxide steel with an internal diameter of 4.4mm, outer diameter of 7mm, and thickness between 1.1-1.3mm, designed specifically for M4 screw sizes. The material hardness is certified at Rockwell C44. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring it is free from hazardous substances and safe for use in various international markets.