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How Do They Get Lead in a Pencil?

Take a look at the writing end of a brand-new wooden pencil before sharpening it; it appears that the wood casing is one solid piece. This might lead you to believe that pencil-makers bore a hole straight down the middle of the wood and then slide in a rod of lead. Although early pencils were constructed in this manner, it is not how most wooden pencils are mass-produced today.

Before discussing how the lead is put into the wood cas­ing, let's clear up what the actual lead is. 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. According to theCumberland Pencil Museum, in the mid-16th century, a violent storm knocked over several trees in Borrowdale, England, uncovering a large deposit of a black substance that was first thought to be lead. More than 200 years later, an English scientist discovered that the substance was not actually lead, but a type of carbon instead. The substance was named graphite, after the Greek word meaning "to write," since that's how people used the substance.

Early pencils were crude versions of today's standard model. The first pencil was just a chunk of graphite used by carpenters and artisans to make markings without denting their materials. This...Read the rest herehttp://science.howstuffworks.com/innovation/science-questions/question465.htm