The hardness of the core is often marked on the pencil -- look for a number (such as "2" "2-1/2" or "3"). The higher the number the harder the writing core and the lighter the mark left on the paper. As the pencil core becomes softer (through the use of lower proportions of clay) it leaves a darker mark as it deposits more graphitei material on the paper. Softer pencils will dull faster than harder leads and require more frequent sharpening.

You might see other markings on pencils. Most pencil manufacturers outside of the US use the letter "H" to indicate a hard pencil. Likewise, a pencil maker might use the letter "B" to designate the blackness of the pencil's mark, indicating a softer lead. The letter "F" is also used to indicate that the pencil sharpens to a fine pont.

Grade swatches 9H to 9B

Historically pencil makers also use combinations of letters -- a pencil marked "HB" is hard and black; a pencil marked "HH" is very hard, and a pencil marked "HHBBB" is very hard and really, really black! Although today most pencils using the HB system are designated by a number such as 2B, 4B or 2H to indicate the degree of hardness. For example a 4B would be softer than a 2B and a 3H harder than an H.

Generally, an HB grade about the middle of the scale is considered to be equivalent to a #2 pencil using the US numbering system.

In reality however there is no specific industry standard for the darkness of the mark to be left within the HB or any other hardness grade scale. Thus a #2 or HB pencil from one brand will not necessarily leave the same mark as a #2 or HB pencil from another brand. Most pencil manufacturers set their own internal standards for graphite hardness grades and overall quality of the core.

Here is a complete grade scale from General Pencil Company's Kimberly brand drawing pencils showing differences in degrees of gradation.

Back to Pencil Leads.