Pencil, An Engineering Miracle

The life of a pencil starts with a cedar tree and finishes with a writer. 14 BILLION pencils are made every year in the world! Pencils are engineered in the US, China, and South America using materials from all over the world.

In the 1500s a storm knocked over trees in Borrowdale, England. Under the trees was a soft black rock. The villagers discovered that they could write with it. Scientists found out that the rock was made of carbon and named it graphite. The first pencil was just a stick of graphite. Later, sticks of graphite were wrapped in string to make them easier to hold. Eventually, strips of wood were put around the graphite. This looked like the pencils we have today. Pencils were engineered differently over 300 years to make them easier to write with.

Even though pencils look simple, they have many different parts. The inside of a pencil is made of graphite and clay. The outside of a pencil is made of wood and holds the graphite in place. The eraser on top is made of rubber mixed with chemicals. A metal ferrule sits around the eraser. And finally, pencils are covered with paint to make them easier to hold. Each part of the pencil has a purpose and is engineered to work together with the other parts.

Every pencil has a different color depending on the amount of graphite and clay. The number printed on the side of a pencil tells you how dark that pencil is. No.1 pencils have the darkest gray writing and No. 4 pencils have the lightest gray writing. Chemical engineers mix graphite and clay for pencils. First, the graphite and clay mixture is pushed through a mold into a thin stick. Then these sticks are dried in an oven. Last,The dried sticks are collected and set to a side. Chemical engineers have worked to make this process as efficient as possible.

The covering for the dried sticks of graphite and clay comes from cedar trees. First, the tree is cut down and the wood is dried. Then the dry wood is cut into narrow strips called slats. After that, a machine makes a groove from the top to bottom of each slat. Then a dried graphite stick is put into the groove. A second slat is put on top of the first and the 2 slats are glued together. Then the pencil is cut around the outside edge to give it a nice shape. Mechanical engineers come up with the best wooden pencil designs, and industrial engineers figure out the best way to put the pencils together in factories.

After the pencil is shaped, it is dipped in paint to give it color. Most pencils are yellow, but some have bright colors and designs. After the paint dries, the glossy outside makes pencils comfortable to hold. A chemical engineer figures out what chemicals to mix together to get the paint for pencils. They make sure that the paint will not rub off when a person is writing. Chemical engineers also have to make sure that the paint is safe and not toxic to people.

Most pencils have an eraser on top. Erasers are made of rubber mixed with pumice and sulfur. The rubber used to come from trees but is now made in factories. This is called synthetic rubber. First, chemical engineers treat the rubber with a chemical called sulfur to make the rubber less hard and more bendable. This way the eraser won’t tear the paper that it rubs. Then a rough powder made of pummice is added to the rubber to help it remove graphite writing. Lastly, the mixture is colored and made into a cylinder shape. Most erasers are colored pink.

The last part of a pencil is the ferrule. Ferrules are made of a metal called aluminum that comes from the ground. Metallurgical and mining engineers work together to mine a mineral called bauxite from the ground. Then chemical engineers turn the bauxite into aluminum. The aluminum is made into thin strips in a factory. The aluminum strip is then rolled into a cylinder ferrule and glued to the top of the pencil. Lastly, the eraser is put inside and the ferrule is clamped around it, to hold the eraser in place.

Now we have a completed pencil! The pencil is packed into a box and shipped to a store for someone to buy. But this isn’t the end of the pencil’s story… the real miracle starts only after you pick it up to write.