How Is Lead Put In A Pencil?

Although we use the term 'lead pencils' the mixture contained in pencils is not actually lead, it is a mixture of graphite and clay.
The graphite and clay are blended with water by machine.  This mixture is then transferred to a second machine which squeezes it out through a very narrow aperture.  It then comes out in the shape of a very long strings.  These are hardened in the oven and treated with wax, so that they can write more easily.
The final stage comes with inserting these 'strings' into the pencil.  The wood which encases the pencil is usually cedar.  This is because it has a soft grain and consequently will not split when it is sharpened.  The cedarwood is cut into narrow strips called slats.  A groove is then cut into each slat and a string of graphite is laid in the groove.  Another slat is glued on the one holding the graphite, the pencil is sanded, painted and a pencil has been formed !