Question 8 of 9: Section view from an isometric pictorial

Question 8: Section view from an isometric pictorial

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

The part is a circular flanged coupling: a disc-shaped flange with a central bore, carrying a stepped cylindrical body (also bored through) rising from its centre. Because the interior bore is not visible in any exterior view without a wall of hidden lines, a FULL SECTION taken on the vertical centreline (cutting straight through the flange and the body) is the appropriate view: it shows the bore’s true diameter and depth as solid, hatched, visible geometry instead of dashed hidden lines.

Approach. Place an imaginary cutting plane through the part’s axis of symmetry, remove the near half, and project what remains: solid material that the cutting plane actually passes through is cross-hatched (thin parallel lines at 45°), while the bore itself is left open (no hatch) since the plane passes through empty space there.

1. Choose the cutting plane. The vertical plane through the common axis of the flange and body gives the most descriptive section, since both the bore and the step in outer diameter lie on that axis.
2. Project the section. Outer profile is the same silhouette as an un-sectioned front view; the bore appears as two parallel solid lines (no longer hidden/dashed) at its true diameter running the full height.
3. Hatch the cut material. Only the flange and body walls that the plane actually slices through are hatched; the open bore stays white.