DIN 661 countersunk head rivet, 6 x 20 mm, Article number 661B06020. Surface finish: plain. Countersunk Head Rivet manufactured to DIN 661. 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: permanent joining of sheet metal, brackets and light structures in fabrication, plant maintenance and marine outfitting.