My pencil says HB, what does it mean?

Tabby Tom

Hard black. Apr 15 03, 9:44 AM

Kainantu

Pencil lead is not lead at {all;} it's a combination of finely ground graphite and clay, mixed with water and pressed together at high temperatures into thin rods. We call it lead is because the Englishmen who first discovered graphite believed they had found lead. Manufacturers label pencils according to their hardness. They can make different hardness by adding more or less of clay or graphite. The pencil HB that you have is in the middle of the hardness/softness scale and is the pencil most used in schools as it is ideal for handwriting. 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. One can also have 2H 3H 4H 5H 6H 7H leads that indicates pencils of increasing hardness and 2B 3B 4B 5B 6B 7B to indicate leads of increasing softness. Soft pencils make a dark, heavy line. Harder pencils make a finer, lighter line. {Sources;} http://www.howstuffworks.com/question465.htm http://science.howstuffworks.com/framed.htm?parent=question465.htm and url=http://www.pencils.com/ www.pencils.com/makeit.html Apr 15 03, 2:10 PM