Grinding /ˈɡraɪndɪŋ/ – metal forming; in this case, products of a round or shaped profile (mainly a screw, wire rod, pipe) (usually cold) are pulled out of the hole (filler); the surface of the output section of the matrix is smaller than the surface of the initial section of the drawn objects. As a result, the cross-sectional size of the product decreases and the length increases. A multi-spinner spinning machine is used to process multiple workpieces at the same time