Sharpen Up!

Did you know that you could draw a continuous line thirty-five miles long with a new pencil before its lead would be all gone? It’s true. And did you ever wonder how a pencil was made or how the thin lead was inserted into the wood?

Before the birth of Jesus Christ, Greeks and Romans were using pieces of lead to write with. Much later—around the 1550s—the English started writing with pieces of graphite. About 1650 the Germans enclosed the graphite in a wooden case. A Frenchman, Nicolas Jacques Conté, invented a pencil manufacturing process in 1795. Surprisingly, the process is basically the same today, except that pencils are now made by machines.

Because it is softer and makes a darker mark, graphite is used in pencils instead of lead. Although found naturally in the earth, graphite can also be easily manufactured; hence, there is always a plentiful supply of it. Graphite to be used for pencils is first ground coarsely. Then it is separated into different degrees of fineness by floating it in tanks of water. The tanks are arranged like steps, and the water flows successively from the top tank into those below it. The coarsest, or roughest, graphite settles to the bottom of the first tank, and the finest graphite settles in the last tank.

After the graphite is dried and powdered, it is mixed with a certain amount of pipe clay, the amount depending on how hard or soft the manufacturer wishes the lead in the pencil to be. Equal parts of graphite and clay produce a hard-lead pencil; more graphite than clay produces a soft-lead pencil.

The clay and graphite are ground together until they are thoroughly mixed and resemble dough. The “dough” is then put into a steel cylinder with holes the size required for the pencil leads. A power-driven piston forces the dough out the holes like wire strings. The lead is then cut into lengths of about 7 1/4 inches (18.4 cm) and dried in an oven. Before being encased in wood, the lead is coated with wax so that it will write smoothly.

The wooden casings are made from cedar logs cut into “blocks” large enough to make nine pencils. The blocks are grooved to hold the right lead size by a machine. After grooving, one block face is coated with glue. Leads are placed into the grooves, and a second grooved block is placed on top. Next the blocks are put into a press under great pressure and left to dry.

When the blocks are dry, they are run through a machine with rapidly revolving knives that cut the blocks into the size and shape pencil wanted. Now the pencils are ready for the finishing touches. The cut pencils are sanded smooth, then painted or varnished and stamped with the name of the manufacturer and the numbers or letters that state the degree of lead hardness so that people know what kind of mark the pencil will make. The last steps are to add an eraser, if wanted, and inspect each pencil.

Today, worldwide, the common wood pencil is still the most popular writing tool.