1.Material:stainless steel,iron 2.Guarantee quanlity 3.Different sizes adn finishing 4. ... manufactry DetailsA.Production Name: Single action spring hinge,/stainless steel spring hinge/door hingeB.Material:Stainless steel,brassC.Finishing:Chrome,Satin,Golden ,ect.D ... .Making Process : Stamping, deep drawing,bending, punching, laster cutting,threading stainless steel ball bearing hinge( 2BB&4BB)