coating is deposited by physical vapor deposition the coating is composed of metal nitrides in combination with alumina the coating is composed of a laminar multilayered structure the insert is further treated to have different outer layers on the rake face and flank face respectively application_number US 51340506 A description the coating preferably made by pvd has a ti al n compound next to the substrate an alumina layer on top of the ti al n layer and at least two further alternating layers of ti al n and alumina and an outermost layer of zrn the zrn layer is removed on the rake face in a post treatment preferably blasting or brushing for complete removal of the zrn coating on the rake face several repeated brushings or blastings are often necessary an incomplete removal often results in local welding of the zrn residuals to the chip which reduces tool life in order to reduce the adherence of the top zrn layer an intermediate layer of substoichiometric zrn 1 x is deposited on the alumina layer underneath the zrn layer the substoichiometric zrn 1 x has a reduced strength and facilitates the removal of the top zrn layer according to the present invention.