S-91128A316 38 mm ID Square Washers

Key Features & Benefits at a Glance

• Exceptional Load Distribution - Square shape with 50mm width provides superior surface contact, preventing fastener loosening and material damage under heavy loads.
• Enhanced Corrosion Resistance - Black-oxide steel coating offers reliable protection against rust and degradation in harsh industrial environments.
• Precision Fit for M30 Applications - 38mm inner diameter ensures perfect alignment with M30 screws, reducing installation time and improving assembly accuracy.
• Superior Mechanical Strength - Rockwell 15N80 hardness rating guarantees consistent performance under extreme pressure and vibration conditions.
• Optimal Thickness for Stability - 6.0mm thickness maintains structural integrity while accommodating standard torque requirements.
• Full Regulatory Compliance - Meets RoHS 3 and REACH standards, ensuring safe use in regulated industries and international markets.
• Metric System Compatibility - Standard metric dimensions facilitate seamless integration with global equipment and machinery specifications.

Professional Applications & Engineering Value

Engineered for demanding industrial applications, this black-oxide steel square washer solves critical challenges in heavy machinery, construction equipment, and structural assemblies. The square configuration provides four-point contact stability that outperforms round washers in preventing rotation and distributing clamp load across wider surfaces. With Rockwell 15N80 hardness, the washer maintains dimensional stability under extreme vibration and pressure cycles common in M30 screw applications. The black-oxide surface treatment creates a protective barrier against moisture, chemicals, and environmental exposure, significantly extending service life in outdoor or corrosive environments. This combination of precision dimensions (38mm ID × 50mm width × 6mm thickness) and material properties delivers reliable performance in bolted connections subject to dynamic loading and thermal cycling.

Specification Summary & Compliance

This metric square washer features precision-engineered dimensions with 38mm inner diameter, 50mm width, and 6.0mm thickness specifically designed for M30 screw applications. Manufactured from high-grade steel with Rockwell 15N80 hardness rating, the component maintains dimensional stability across industrial temperature ranges. Compliance includes RoHS 3 (2015/863/EU) with exemption 6(a) for lead as an alloying element in steel, and full REACH (EC 1907/2006) compliance with the latest SVHC requirements as of January 2023. The black-oxide finish provides consistent corrosion protection while meeting international standards for industrial fastener applications.