✓ Skill valued by every manufacturing company
✓ Essential for mechanical engineering
✓ Used in architecture, civil engineering
✓ Required for product design
✓ Competitive advantage in technical roles
✓ Often tested in technical interviews

CONTINUOUS THICK LINE (___)
- Visible edges
- Outlines of the object
- Used most frequently

CONTINUOUS THIN LINE (---)
- Dimension lines
- Projection lines
- Reference lines

DASHED LINE (- - -)
- Hidden edges
- Features not visible from this view
- Behind other surfaces

CENTER LINE (—·—·—)
- Axes of cylinders
- Center points of circles
- Lines of symmetry

CHAINCDALE LINE (——··——··)
- Special surfaces
- Cutting planes
- For emphasis in design

FULL SCALE (1:1)
- Drawing size = actual size
- Used for small objects
- Example: Bolt drawing

REDUCED SCALE (1:2, 1:5, 1:10)
- Drawing smaller than actual
- Used for large objects
- Example: Machine layout (1:10 scale)

ENLARGED SCALE (2:1, 5:1, 10:1)
- Drawing larger than actual
- Used for tiny components
- Example: Circuit board details (5:1 scale)

Importance: Always mark scale clearly!

FRONT VIEW (Elevation)
- Looking at object from front
- Shows height and width
- Most important view
- Always include this

TOP VIEW (Plan)
- Looking down from above
- Shows length and width
- Reveals overall shape
- Essential for understanding depth

SIDE VIEW (Profile)
- Looking from the side
- Shows height and depth
- Completes 3D understanding
- Often the right side view

How they relate:
- Width same in front and top
- Height same in front and side
- Depth same in top and side
- Alignment is crucial!

FIRST ANGLE (Used in India/ Europe):
- Orthographic views positioned differently
- Top view below front view
- Side view to the left
- Symbol: ◊ pyramid pointing up

THIRD ANGLE (Used in USA/Japan):
- Different view arrangement
- Top view above front view
- Side view to the right
- Symbol: ◊ pyramid pointing down

Impact: Different arrangement of same views
Must check which standard is being used!

✓ Place dimensions outside the object
✓ No dimension should be repeated
✓ Related dimensions grouped together
✓ Dimensions placed on views where feature is clear
✓ Maintain minimum spacing between dimension lines
✓ Always include units (mm, cm, inches)

✗ Never place dimensions inside the drawing
✗ Don't overcrowd with dimensions
✗ Never use a line for two purposes
✗ Avoid dimensioning in cross sections

BASIC DIMENSION:
- Simple distance measurement
- Example: Length 50 mm, Width 30 mm

RADIUS vs DIAMETER:
- Radius (R 20): From center to arc
- Diameter (Ø 40): Full width of circle
- Radius = Half of diameter
- Always use: R for curves, Ø for holes

ANGULAR DIMENSION:
- Angles in degrees (°)
- Example: 45°, 90°, 120°
- Measured from horizontal or vertical

CHAIN DIMENSION:
- Dimensions in sequence
- One after another
- Used for step features
- Example: 10-20-15 (total 45)

CIRCLE VIEW:
- Shown as full circle
- Diameter marked with Ø
- Example: Ø 25 mm hole

CYLINDER VIEWS:
- Front: Rectangle (height × width)
- Top: Circle (diameter)
- Shows 3D nature

Arc and Curves:
- Drawn with center point
- Radius marked from center
- Used for rounded corners

TRIANGLE:
- 3 sides, 3 angles
- Total angles = 180°
- Types: Equilateral, Isosceles, Right-angled

SQUARE/RECTANGLE:
- 4 sides, 4 right angles (90°)
- Square: All sides equal
- Rectangle: Opposite sides equal
- Total angles = 360°

HEXAGON:
- 6 sides (nut shapes)
- Total angles = 720°
- Common in mechanical parts

FULL SECTION:
- Cutting plane goes completely through
- Shows full internal structure
- Uses hatching to show cut surface

HALF SECTION:
- Cutting plane goes halfway
- Shows inside and outside
- Left: Internal details
- Right: External outline

HATCHING PATTERNS:
- Cast Iron: Diagonal lines (thick)
- Steel: Diagonal lines (45°)
- Copper: Diagonal lines (60°)
- Aluminum: Dotted pattern
- Wood: Cross-hatching

Hiding Hatching:
- Use visible lines to hide hatching
- Hatching shouldn't cross object lines

ISOMETRIC AXES:
- Horizontal axis: 30° from horizontal
- Vertical axis: Straight up (90°)
- Receding axis: 30° downward
- All dimensions at 1:1 (true length)

ISOMETRIC vs ORTHOGRAPHIC:
- Isometric: Single 3D view
- Orthographic: Multiple 2D views
- Both accurate, different purposes

TITLE BLOCK (Bottom right corner):
- Product/component name
- Drawing number/ID
- Scale used
- Date of drawing
- Drawn by: Name
- Checked by: Name
- Company/Institution
- Version number

NOTES SECTION:
- Special instructions
- Manufacturing notes
- Assembly information
- Quality standards

MATERIAL SPECIFICATION:
- Material type (Steel, Aluminum, Plastic)
- Grade/specification
- Finish (Paint, Anodized, etc.)

✗ Crossing dimension lines
✗ Misaligned orthographic views
✗ Inconsistent line weights
✗ Missing dimensions
✗ Unclear scale information
✗ Poor title block information
✗ Incorrect projection method
✗ Messy erasures and corrections
✗ Dimensions not parallel to edges
✗ Using ruler instead of instruments for circles

✓ Use proper drawing instruments
✓ Keep drawings clean and organized
✓ Double-check all dimensions
✓ Verify scale before submitting
✓ Add clear notes and annotations

1. Draw simple 2D shapes (square, rectangle)
2. Practice line types and weights
3. Draw basic orthographic views of cubes
4. Practice dimensioning simple objects
5. Learn to use drawing tools (compass, scale)

1. Draw cylindrical objects (tubes, pipes)
2. Create orthographic views of complex shapes
3. Practice sectional views
4. Add proper dimensions with standards
5. Create assembled drawings of multiple parts

1. Isometric drawings from orthographic views
2. Detailed sectional views with hatching
3. Assembly drawings
4. 3D CAD to 2D technical drawing
5. Manufacturing specifications and notes

✓ Drawing board (smooth, flat surface)
✓ T-square or parallel ruler (horizontal lines)
✓ Set squares (30-60° and 45-45° angles)
✓ Compass (circles and arcs)
✓ Scale ruler (measurements)
✓ Pencil (HB, H for thin lines, B for thick)
✓ Eraser (soft, for pencil)
✓ Divider (transferring distances)
✓ Temples (curves)
✓ Drafting tape (holding paper)

✓ CAD Software: AutoCAD, SolidWorks, FreeCAD
✓ Advantages: Precise, editable, printable
✓ Faster for complex drawings
✓ Easy to add annotations
✓ Can generate views automatically

MECHANICAL ENGINEERING:
- Machine parts and assemblies
- Product design
- Manufacturing drawings

CIVIL ENGINEERING:
- Building plans
- Architectural layouts
- Construction details

ELECTRICAL ENGINEERING:
- Circuit diagrams
- Cabinet layouts
- Wiring schematics

AUTOMOTIVE:
- Vehicle components
- Assembly drawings
- Maintenance manuals