Abstract: A filter for a machine tool operative to filter one of steel, brass, and copper from a liquid agent is disclosed herein. The filter consists of a cylindrical container having a closed top end and a closed bottom end, an upper duct positioned near the top end of the container, a lower duct positioned near the bottom end of the container and having a lower diffuser fluidly connected thereto, and a filtering element surrounding the lower diffuser. The filter element consists of ilmenite particles having a density (d) of about 6 g/cm.sup.3 and a size ranging between a smallest size of about 0.2 mm and a largest size of about 1.0 mm, the ilmenite particles being in the form of grains having sharp edges and irregular sized faces.