TECHNICAL DRAFTING: ALPHABET OF LINES.pptx

TECHNICAL DRAFTING

1. Technical Drawing: Alphabet of Lines

2. Technical drawing: alphabet of lines Technical drawing, is the act and discipline of composing drawings that visually communicate how something functions or is constructed. Line, can be defined as a straight one- dimensional figure that has no thickness and extends endlessly in both directions. It is often described as the shortest distance between any two points.

3. OBJECT OR VISIBLE LINES - Thick dark line use to show outline of object, visible edges and surfaces.

4. CONSTRUCTION LINE - Very light and thin line used to construct layout work

5. DIMENSION LINE Thin and dark lines use to show the size (span) of an object with a numeric value. Usually terminates with arrowheads or tick markings

6. EXTENSION LINE Thin and dark line use to show the starting and ending of dimension.

7. HIDDEN LINE Short dash lines use to show non visible surfaces. Usually shows as medium thickness.

8. Center LINE Long and short dash lines. Usually indicates center of holes, circles and arcs. Line is thin and dark.

9. CUTTING PLANE LINE Extra thick line use to show cutaway views or plane of projection where a section view is taken. Arrow indicates direction of view.

10. SECTION LINE Medium lines drawn at 45 degrees use to show interior view of solid areas of cutting plane line.

11. SHORT AND LONG BREAK LINES Short and long medium line use to show cutaway view of a long section.

12. LEADER LINE Medium line with arrowhead to show notes or label for size or special information about a feature.

13. PHANTOM LINE Long line followed by two short dashes use to show alternate position of a moving part.

14. What’s more? Activity #5: Let’s Try it on the Board! Directions: Draw the lines needed to complete the drawing plan of different geometrical shapes.

15. What’s more? Activity #5: Let’s Try it on the Board! pyramid: Hidden line

16. What’s more? Activity #5: Let’s Try it on the Board! circle: Center line

17. What’s more? Activity #5: Let’s Try it on the Board! Cube: Extension line and dimension line

18. What’s more? Activity #5: Let’s Try it on the Board! cylinder: Cutting plane line and Section line

19. Technical drawing: alphabet of lines OBJECT OR VISIBLE LINES CONSTRUCTION LINE DIMENSION LINE HIDDEN LINE CENTRE LINE EXTENSION LINE CUTTING PLANE LINE SHORT AND LONG BREAK LINES LEADER LINE PHANTOM LINE SECTION LINE

20. What have I learned? Activity # 8: Let’s Check your Understanding Post – Test. Directions: Read each statement carefully with understanding. Write the letter of the correct answer before each number.

21. Let’s Reflect: I understand that_______________________ I realize that____________________________

22. THANK YOU