We manufacture and export Serrated Washer which are designed specially that makes them ready to fit with the capacity to sustain preload and avoid loosening. These Serrated Safety Lock Washers are extensively used because of their wide application area and flexibility. Metric Serrated Washers : Size Minimum Thickness External Diameter M16 3.7 25.5 M20 3.9 32.5 M25 3.9 40.0 M32 3.9 43.5 M40 3.9 64.5 M50 3.9 80.0 M63 3.9 100.0 M75 3.9 112.0 M90 4.1 135.0 M100 4.1 144.6 M115 4.1 159.0 NPT Serrated Washers : Size Minimum Thickness External Diameter 1/2" NPT 0.152 1.268 3/4" NPT 0.152 1.560 1 " NPT 0.152 1.697 1-1/4 " NPT 0.152 2.516 1-1/2 " NPT 0.152 3.120 2 " NPT 0.152 3.900 2-1/2 " NPT 0.159 4.368 3 " NPT 0.159 5.265 3-1/2 " NPT 0.159 5.639 4 " NPT 0.159 6.201 Material : Stainless Steel 316L grade and also available in mild steel with Zinc Plating. Standard: DIN 6798J. Application : Used for high vibration resistance due to positive equipment contact. Excellent pretensioning. Through proper radius selection, no splitting/cracking occurs during tightening. Extensive application and flexibility, minimizes stocks.