1. 2 Line Conventions and Lettering

2. Unit 2 Objectives Identify the standard alphabet of lines. Describe the types of lines by appearance and purpose. Identify the style of lettering recommended for standard industrial drawings.

3. Line Conventions A convention is a generally accepted way of doing something A list of line types is used throughout industry to show the conventional practice for industrial prints This list is defined in many references as the alphabet of lines

4. Alphabet of Lines Most common line types: Visible lines Hidden lines Center lines

5. Visible Lines

6. Hidden Lines and Center lines

7. Alphabet of Lines Line types used in section views: Section lines Cutting-plane lines Short break lines

8. Lines Types Used in Section Views

9. Alphabet of Lines Line types used in dimensioning: Extension lines Dimension lines Leader lines

10. Lines Types Used in Dimensioning

11. Alphabet of Lines Additional line types: Break lines Phantom lines Stitch lines Chain lines

12. Describe in terms of the alphabet of lines the lines that appear in this illustration

13. Lettering In engineering drawings, the text and numeric information is referred to as lettering Lettering is: Uppercase Vertical structure Single stroke Gothic CAD drawings use the same fonts as word processing documents.

14. NEXT UP: You will now review drawing AP-001 and discuss the way the lines communicate the size and shape of the mechanical part.