DIN 988 round flat washer, 4 x 8 x 0.1 mm, shim ring, Article number 988040801. Property class / material: steel, surface finish plain. Round Flat Washer manufactured to DIN 988. Standard parts to the same standard, property class, dimensions and surface finish are interchangeable between manufacturers; confirm the controlling standard revision, any class-society or application approval, and the mating thread before substitution. Applications: load distribution and locking under bolt heads and nuts in machine building, structural steel, plant maintenance and marine outfitting.