DEGREES OF HARDNESS

Adjustment of the hardness by varying the mixing ration of graphite to clay. The more clay versus graphite is introduced into the mixture, the "harder" the writing action of the pencil will become. 

The identification of a lead´s degree of hardness is expressed in letters and numbers.

Harder Leads:          Letter H  (H=hard)

Softer Leads:            Letter B (B=black)   

The added number indicates increasing blackness or hardness. For instance, a 6H lead is harder than a 4H.

Correct Application:

Precise technical drawing:              harder pencil

Artistic drawing:                            softer pencil

Writing (Office):                            HB

Writing (Students):                        2B