DIN 128-A spring lock washer (form A), 2.1 x 4.4 x 0.5 mm, Article number 128AA4021. Made in stainless steel a4. Spring Lock Washer manufactured to DIN 128. 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.