Pencil makers in the United States often use a number scale in which higher numbers mean harder graphite, while manufacturers in other countries often use a letter scale that grades based on hardness, blackness and ability to sharpen. However, these marks vary as manufacturers employ their own gradi
A typical No. 2 pencil is 7.5 inches long with a 6.75-inch wooden shaft. Most No. 2 pencils are made from cedar with a hexagonal shaft. The lead is a mixture of graphite, clay and wax.
The lead inside a pencil is made of a combination of graphite and clay. Fine graphite particles are mixed with the clay to form a paste. The paste is fired in a kiln and treated with wax.
The length of a standard number 2 pencil is 7.5 inches, and the pencil has a diameter of about 7 millimeters. Golf, or library, pencils are typically about 3.5 inches long. The most common material used for a pencil's core is graphite.
Although the exact inventor of the pencil is unknown, Conrad Gesner is often credited with the invention. In 1565, Gesner was the first to document the use of graphite placed in a wooden shaft, which was the predecessor to modern pencils.
The "lead" contained in most pencils is not actually lead, but rather nontoxic graphite and is, therefore, not poisonous or dangerous to humans, according to Pencils.com. However, any puncture wound in the skin should be treated to avoid infection and other health issues.
The pencil was first invented in Borrowdale, England, in the mid-1500s. Early pencils were not encased in wood, but were actually fragile rods of graphite that had to be strengthened by a string casing. Craftsmen eventually began to fashion hand-carved wooden cases to hold the graphite.
Grease pencils are used for writing on surfaces that are nonporous, hard and usually glossy. Some examples of surface materials appropriate for a grease pencil are lacquered maps, glass and ceramics.
The density of a pencil varies based on the type of pencil, but it can be found by measuring the pencil's mass, preferably in grams, and then dividing the mass by the volume. The formula for density is density = mass/volume.
A simple and effective way to sharpen a pencil is to use a hand-held pencil sharpener. Insert a pencil into the pencil sharpener. Firmly grasp the pencil sharpener and turn the pencil clockwise until it is sharp enough, periodically checking the pencil's sharpness.