These 100 Thin Brass Circle Blanks measure 16 mm in diameter or 5/8 inches. This metal round blank is about .33 mm thick and is perfectly flat. These brass stamping tags are great for all kinds of jewelry making projects, crafts and other fun projects. Use these stamping blanks for scrap booking embellishments, keychains, charms and more! This soft brass blank is great to work with and easy to stamp. Use with a hardened or tempered steel metal design, letter or number stamps.