Features Use to permanently mark tools, components, nonmetals, and various metals. Designed for deeper marking in industrial applications and can be applied on soft and hard metals without heat treatment. For manual (tempered stamping head) or mechanical use. Character and size are indicated on the thumb side. Impressions are Gothic letters. Character Height / 3/8 inch Shank Length / 3 1/8 inch Shank Size Square / 9/16 inch Material / Steel Hardness / 58 to 62HRC at the Engraving End and 38 to 46HRC at the Striking End Case Material / Plastic Impression Letter Type / Gothic Includes / (9) Pieces - 0 thru 8 with 6 Serving as 9