ENGINEERING DRAWING

BASICS OF LETTERING

1. NEED FOR LETTERING
Lettering is needed for


• Dimensions of parts
• Notes relating to the manufacture of parts
• Descriptive titles.


Shall be
• Highly legible
• Uniform
• Capable of being done rapidly

,2. CONSIDERATIONS FOR GOOD LETTERING


A. General Proportions
• No specific standard for the proportions of letters
• Proportion of width to the height of letters varies.
• Low and extended letters are more legible than high compressed
ones.


B. The Rule of Stability
• In order to give the appearance of stability, letters as B, E, K, S, X,
and Z and the digits 3 and 8 must be drawn smaller at the top than at
the bottom.


C. Guide Lines
• Always draw light guide lines for both tops and bottoms of letters. A
very sharp pencil shall be used for the purpose.

, D. Styles of Lettering
• No specific standard for the style of lettering
• Styles shall be simple and clear to facilitate the reading of a drawing.
• TIME-CONSUMING LETTERING STYLE
• AN EFFICIENT LETTERING STYLE
• A LIMITED-USE LETTERING STYLE


E. Size of Lettering
• Shall be at least 0.125 in (3.00 mm) high


F. Aspect Ratio
• The width/height ratio
• No specific standard