Pencils now contain no lead, but are made of graphite and clay, so named because of its historical evolution. In ancient Greece and Rome, lead bars similar to pencils were made of metallic lead. Most of them are conical, which will leave traces of lead after rubbing with other objects for marking. /kloc-in the 0/4th century, a pencil similar to the present appeared in Europe. From 65438 to 0565, Britain began to make the most primitive wooden pencils by hand, with graphite as the refill. 1662, Germany built the world's first pencil factory. From 1790 to 1793, Kant in France used clay bonded graphite to make refills, which laid the foundation for modern pencil industry. There is usually a hardness mark on the pencil shaft, H stands for hard pencil, and the greater the number in front, the greater the hardness; B stands for soft pencil. The bigger the number in front, the softer the refill. HB stands for pencil with moderate hardness, suitable for daily writing.