Process — How wooden pencils are manufactured

The diagram shows how wooden pencils are made, following two separate streams of material that come together midway through the process.

Overall, the pencil lead and its wooden case are produced independently — the lead from minerals, the case from cedar — and are united at a distinctive sandwich stage, after which the joined block is cut into individual pencils and finished.

The lead comes first. Graphite and clay are mined and ground into powder, mixed with water, squeezed into thin rods and baked hard in an oven. The result is the familiar thin, brittle pencil lead. Meanwhile, on the second stream, cedar wood is cut into small flat slats, and shallow grooves are machined along each one.

The two streams now meet. Leads are laid into the grooves of one slat, and a second slat is glued on top, forming a sandwich with the leads sealed inside. This sandwich is then cut lengthways into single pencils, which are shaped into the usual hexagonal form. Finally each pencil is painted, stamped with its brand, sharpened at one end, and boxed for shipment.