http://www.funtrivia.com/askft/Question31647.html:The letter 'H' is used to indicate a hard pencil. The letter 'B' is used to indicate a soft lead that gives a black result. H â¦ arder pencils make finer lines and softer make thick heavy lines. It's a continuum. H (2H, 4H, etc) are the harder leads, and therefore draw a lighter line; and B (2B, 4B, etc) are the softer leads, and therefore draw a darker line. HB is the very middle. The larger the number, the farther away from HB it is.