S-91100A351 8.5 mm ID x 20.7 mm OD DIN 7349-A Oversized Washers

Key Features & Benefits at a Glance

• Enhanced corrosion resistance with zinc plating, extending service life in demanding industrial environments
• Optimal load distribution for Class 8.8 fasteners, preventing surface damage and maintaining joint integrity
• Precision dimensional accuracy (8.5mm ID, 20.7mm OD, 3.7-4.3mm thickness) ensuring consistent fit and performance
• DIN 7349-A compliance guaranteeing standardized quality and interchangeability in European machinery applications
• Environmental regulation adherence with full RoHS 3 and REACH compliance for safe, sustainable sourcing
• Robust steel construction providing reliable strength without hardness-related brittleness in high-stress assemblies
• Simplified inventory management through metric system standardization and clear M8 fastener compatibility

Professional Applications & Engineering Value

This zinc-plated steel flat washer delivers critical engineering solutions for industrial equipment maintenance and heavy-duty machinery assembly. The M8-compatible design with DIN 7349-A standardization addresses common challenges like galvanic corrosion and joint loosening under dynamic loads. Its 20.7mm outer diameter creates an optimal bearing surface that redistributes clamping force from Class 8.8 fasteners, preventing embedment in soft materials and maintaining torque specifications. The zinc plating provides sacrificial protection against moisture and chemicals, while the controlled 3.7-4.3mm thickness range ensures uniform pressure distribution without compromising assembly stack height. These characteristics make it indispensable for automotive subframes, construction machinery, and manufacturing jigs where vibration resistance and long-term reliability are paramount.

Specification Summary & Compliance

Manufactured to DIN 7349-A standards with metric dimensions (8.5mm ID × 20.7mm OD × 3.7-4.3mm thickness) for M8 fastener applications. Compatible with Class 8.8 fastener strength grades. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, including SVHC requirements updated June 2023. Material: zinc-plated steel.