S-98040A104 6.4 mm ID x 18 mm OD Oversized Washers

Key Features & Benefits at a Glance

• Enhanced corrosion resistance through black-oxide steel surface treatment, extending service life in demanding industrial environments
• Superior load distribution with precise 18mm OD and 4.0-4.9mm thickness, preventing surface damage and maintaining joint integrity
• Reliable hardness performance at Rockwell 15N80, ensuring consistent performance under mechanical stress
• Perfect M6 screw compatibility with 6.4mm ID, providing secure fastening without play or misalignment
• Full regulatory compliance with RoHS 3 and REACH standards, meeting global environmental and safety requirements
• Metric system precision ensuring seamless integration with international engineering specifications and replacement parts
• Durable steel construction offering excellent strength-to-weight ratio for heavy-duty applications

Professional Applications & Engineering Value

These M6 flat washers deliver exceptional engineering value through their black-oxide steel composition and precise dimensional control. The black-oxide surface treatment provides superior corrosion resistance, solving common industrial challenges where moisture, chemicals, or environmental exposure compromise fastener integrity. With Rockwell 15N80 hardness, these metric washers maintain structural stability under high clamping forces, preventing deformation in critical assemblies. The optimized 18mm OD and 4.0-4.9mm thickness ensure maximum surface contact distribution, protecting sensitive materials from damage while maintaining bolt tension. Ideal for automotive, machinery, and structural applications, these industrial washers offer reliable performance where vibration resistance and long-term durability are essential.

Specification Summary & Compliance

This M6 flat washer maintains precise metric dimensions with 6.4mm inner diameter, 18mm outer diameter, and 4.0-4.9mm thickness range. Manufactured from black-oxide steel with Rockwell 15N80 hardness rating, the product complies with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as an alloying element in steel and meets REACH (EC 1907/2006) compliance standards as of January 17, 2023. The flat washer design follows standard metric specifications for M6 screw applications, ensuring proper fit and function in industrial fastening systems.