The pencils used for technical drawing differ in some ways from ordinary pencils. Technical drawing pencils have harder lead cores, which results in more precise lines while making the point of the pencil less likely to break. The most commonly used technical drawing pencils are labeled with a number and letter code, such as HB, H, and 2H.

What is a Drafting Pencil? A Drafting pencil/Technical pencil is a particular type of mechanical pencil used by architects, drafting technicians, and designers for precision technical drawing. They have a long slim lead sleeve/guide pipe to aid in marking straight lines with rulers and stencils.

Engineering drawings can be constructed with two or three hardness grades (4H, F and B). Pencils and pencil leads are available in a variety of hardness levels. A hard pencil is used to lay out light lines that are not intended to be seen by the reader.