Harfington 4Pcs Leather Hollow Punch Hex Shank For Drills, 16Mm Dia Hole Punch Size - 16mm leather hole punch, shank dia 1/4?, total length 78mm. Material - This hardened punch is made from heat-treated carbon steel, making it strong and durable. The sharp punch makes drilling easier. Feature - Special design, chip removal fast to make nice clean cuts. Hex shank hollow punch work with power drills or drill presses can easily cut through multiple layers of fabric. Application - Widely used for punching in leather, paper, soft plastic, rubber, PVC board, clothes, shoes, canvas, and other materials. Note - Use a backer board (plywood/soft gasket) during the punching operation, avoiding cutting into your workbench.