S-91128A312 18 mm ID Square Washers

Key Features & Benefits at a Glance

• Superior load distribution with 50mm width and 6.0mm thickness to prevent surface damage and fastener loosening under heavy loads
• Enhanced corrosion resistance from black-oxide steel coating, extending service life in demanding industrial environments
• Precision M14 screw compatibility with 18mm inner diameter ensuring perfect fit and secure fastening in metric applications
• Exceptional hardness rating of Rockwell 15N80 maintains structural integrity under high-pressure conditions
• Square design advantage provides increased surface contact area compared to round washers for superior stability
• Regulatory compliance assurance with RoHS 3 and REACH standards for safe use across global industrial markets
• Durable steel construction delivers reliable performance in heavy machinery, construction, and manufacturing applications

Professional Applications & Engineering Value

This black-oxide steel square washer addresses critical engineering challenges in heavy-duty industrial applications where vibration resistance and load distribution are paramount. The square washer design with 50mm width creates a larger bearing surface than traditional round washers, effectively preventing embedment into soft materials and distributing clamping forces more evenly. The Rockwell 15N80 hardness ensures the washer maintains its structural integrity under extreme pressure, while the black-oxide surface treatment provides essential corrosion protection in humid or chemically aggressive environments. Engineered specifically for M14 metric screws, this washer solves alignment issues in structural steel connections, machinery assembly, and heavy equipment manufacturing where precise load distribution is critical for long-term joint integrity and safety.

Specification Summary & Compliance

This metric square washer features precise dimensional specifications including 18mm inner diameter, 6.0mm thickness, and 50mm width for optimal performance with M14 fasteners. Manufactured from high-grade steel with black-oxide coating and hardened to Rockwell 15N80 specification, the product complies with RoHS 3 (2015/863/EU) under exemption 6(a) for lead as an alloying element in steel and is fully REACH (EC 1907/2006) compliant with the latest SVHC list (01/17/2023, 233 substances), ensuring regulatory acceptance for industrial applications worldwide.