What is a Sectional View? Definitions and Examples of Sectional Drawings for Students

Sectional drawings show what an object looks like as if it had been cut open or sliced through.

• A ‘section line’ or ‘cutting plane‘ is drawn to show where the item has been ‘cut’ (the arrows show the direction the section is viewed from)
• An object is usually ‘cut’ in a place that shows the most internal detail
• Label both the section line and the section with the same letters, i.e. Section ‘A-A’
• Show what would be seen if you look in the direction of the arrows
• Sections are useful for showing how things are put together or assembled
• Cut surfaces have diagonal ‘hatching‘ (angled parallel lines)
• Pins, dowels, bolts, nuts etc are not sectioned (because the purpose of a sectional drawing is usually to show where these items go)
• Do not show hidden detail

Hatching guidelines for cut surfaces

• Hatching lines should be parallel & evenly spaced
• Lines can be on any angle (common to start with 45° lines) but must not be same angle as edge of object
• Avoid having hatching that is parallel to one edge of the area
• Hatch different areas on different directions
• Hatching lines should be thin and approximately 2-4mm apart
• Do not hatch any thin items like pins, dowels, bolts, nuts etc
• When thin surfaces are cut through, they can be coloured black. This should only be for thicknesses less than 1mm

• If hatching really large areas, hatching can only be partially drawn, near the edges

Half Sections

• Sections lines in which only half of the object is cut away
• Usually used when the object is symmetrical
• Allows both the external and internal view to be shown within one drawing

Part Sections

• These are used when only small areas need to be cut away in order to show important details
• The line where the part section ends is simply a thin wavy continuous line (as if part of the surface has been ‘torn’ away)

Revolved Sections

• Shows a cross section rotated so that it can be seen
• It is drawn in place on the normal view

Removed Sections

• Removed section are revolved sections that have been moved away from the main view

Offset sections

• The cutting plane can change directions and turn corners so that the most detail is shown (this is called an offset section)

Sample examination questions (IGCSE Paper 5)