GROZ Number Stamp Set is ideal for permanent hand-stamped imprints on metals, wood, leather, clay, plastic etc. It comes with 58-62 HRC hardened stamping end that leaves clear and burr free impressions without any splintering. It has chamfered and 35-42 HRC tempered striking end that prevents breakage and accidents due to flying splinters, making it safe to use. It comes in easy to store and carry plastic case. Stamp Size: 5 mm (3/16â€)