A cutting insert (100, 200) for cutting, milling or drilling of metal comprises a body having an elongate recess (111, 1111) extending along at least a portion of the body, a first layer (120, 1120) covering interior side walls (112, 113) of the recess, and a sensor arrangement. The body comprises a substrate (110). The sensor arrangement comprises a lead (130, 230, 240) extending along the recess. The lead comprises electrically conductive material which is arranged in the recess such that the first layer is located between the electrically conductive material and the substrate. For at least a depth (D1, D2, D5) below which at least a portion of the electrically conductive material is arranged in the recess, a width (W2, W3, W4) of the recess measured at that depth between portions of the first layer covering opposite interior side walls (112, 113) of the recess is less than or equal to 80 micrometers.