The history of pencils dates back to the discovery of graphite in the 16th century. In 1564, a large deposit of graphite was found in Borrowdale, England, where people initially used it to mark ...

Since both mechanical pencils and the regular kind contain similar “lead” (a combination of graphite and clay), the primary decision here comes down to whether you’d prefer your kids buy ...

Sometime between 1500 and 1565 a large graphite deposit was discovered in Cumbria, England. Because the graphite was extremely pure and solid it could easily be sawed into sticks.

This is, as Petroski notes sternly, “one definite shortcoming of mechanical pencils that cries out for improvement.” Yet other ingenious enhancements have appeared.

As Scientific American reports, “NASA ordered 34 mechanical pencils from Houston’s Tycam Engineering Inc., in 1965. They paid $4,382.50 or $128.89 per pencil.” ...

Get some 0.5mm solder and a .5mm mechanical pencil and you're most of the way there. Remove the eraser, empty all the graphite out of the pencil, and carefully thread the solder into the pencil.