What does the abbreviation "HB" mean?

The abbreviation "HB" means: Hardness of pencil lead, Hardness Black; it is the abbreviation of HardnessBlack.

Pencil specifications are usually expressed in H and B, "H" is the English "Hardness" (hard) of the beginning of the letter, indicating the hardness of the pencil lead, the larger the number before the H, indicating that the more clay contained in it, the harder its lead core, the lighter the color. The larger the number before H, the more clay it contains, the harder the lead core and the lighter the color.

"B" is the initial letter of the English "Black" (black), indicating the degree of blackness and softness of the pencil lead, the larger the number in front of the B, the more graphite represents the component, the thicker and blacker the color of the lead.

HB pencil is a kind of pencil. HB means hardness or gray scale is in the middle (slightly blackish). HB pencil is mainly used for writing, its handwriting color is darker than H pencil, but it is easier to erase than B pencil.

Expanded Information:

p>Pencils are categorized according to the ratio of graphite to clay in the lead core. They are generally divided into three categories:H, HB (including F), and B.

Type H pencil core has high hardness and is suitable for woodworking marking, mechanical drawing and other objects with hard or rough interfaces.Type HB pencil core has moderate hardness and is suitable for general writing (writing).

Type B pencils have softer lead cores and are suitable for drawing (especially painting), of which type 2B pencils are used to fill in some machine-readable cards, such as answer sheets. Also common are colored pencils, also known as crayons, which are mainly used for drawing.