Reading orthographic views

Pick the view that belongs in the empty box. Get 10 right to finish. The picture on the left shows the solid.

How to read it

1. Find the front view. The arrow marked FRONT on the picture shows which side that is.
2. Work out which view belongs in the empty box. That depends on the projection: see first and third angle projection.
3. Line it up. The top view is as wide as the front view. The side view is as tall as the front view.
4. Look for every step in the solid. Each one shows as a line in the views that see it.

In the top view the front of the part is at the bottom edge, in both systems. In the right side view the front of the part is on the left. In the left side view the front is on the right.

These exercises show visible edges only. Real drawings also show hidden edges as dashed lines.

Common mistakes

• Picking the mirror image. A left side view looks like a flipped right side view, but the steps are on the other side.
• Turning the top view upside down. The front of the part is at the bottom of the top view.
• Ignoring the projection. The box next to the front view holds a different view in first angle than in third angle.

Questions

What are orthographic views?

Flat views of a part, each looking straight at one side: front, top, side. Together they describe the full shape. Most parts need two or three views.

Why do the views line up?

They are projected from each other. The top view is as wide as the front view and sits in line with it, and the side view is as tall as the front view. You can carry a point from one view to the next with a straight line.

What does a line inside a view mean?

Usually an edge where two surfaces meet, such as the top of a step. In the top view a line between two areas means they are at different heights.

Explained in our own words and checked against several textbooks. For the full rules, see ASME Y14.2, ASME Y14.3, ISO 128, ISO 5456-2, ISO 7200 and ISO 2768-1.