Knurling: Takes advantage of a Instrument to create a tough surface texture to the function piece. Commonly made use of to permit grip by hand on a metal component. Grinders have amplified in dimension and complexity with improvements in time and know-how. With the old days of the guide toolroom https://www.bizmakersamerica.org/santa-ana-ca-united-states/professional-services/hand-crafted-metalworks