FIELD: the invention refers to the field of processing materials by cutting. ^ SUBSTANCE: the instrument has a holder and located on it a cutting plate. For increasing technological characteristics the cutting plate is fulfilled in the shape of a three-edged pyramid or a truncated pyramid or a prism with a three-cornered foundation having flat or/and fashioned surfaces. At that the maximal thickness of the cutting plate is defined depending of the height of the holder. The cutting plate is mounted due to welding or is formed by welding deposition. ^ EFFECT: increases technological characteristics of the cutting plate. ^ 2 dwg
