Pencils are generally bounded by HB, and to the left of HB are H, 2H, 3H, 4H, 5H, 6H, etc. , are hard lead, 6H is of course the hardest. Generally, it is only 4 hours in most places, because it is already very hard.

Conversely, the right side of HB, that is, B, 2b, 3b, 4b, 5b, 6b, 7b, 8b, 9b, 10b are all soft lead. 10B is the softest number.

Therefore, HB is neither soft nor hard, which is most suitable for drawing and writing (non-original).