Working drawings

Working drawings are sent from a designer to a manufacturer to enable them to build a product.

Exploded diagrams

Exploded diagrams show how a product can be assembled and how the separate parts fit together, with dotted lines showing where the parts slide into place. The diagrams also show components that would usually be hidden in a solid drawing.

An exploded diagram showing how the different components of a knock-down joint fit together, including dotted lines for instruction.

Exploded diagrams can take the place of detailed written instructions, meaning they can explain the construction of something without the barrier of different languages. They are widely used as instructions for self-assembly furniture.


Elevations are the sides of an item you can see on the drawing, eg front elevation or side elevation. The top is referred to as the ‘plan’. These drawings enable detailed measurements to be added for every section of the product.

Isometric drawing showing the plan, side and front elevations.

This isometric drawing shows the plan and front and side elevations of the shape.

Orthographic projections

Orthographic projections are working drawings in either a first or third angle projection and show each side of a design without perspective, ie a 2D drawing of a 3D object. They are used to show an object from every angle to help manufacturers plan production. Starting with a front view of a product, construction lines show where areas join and are used to draw a side and plan (top) view, ensuring that the drawing is accurate from all angles. These drawings are to scale and must show dimensions.

First and third angle projections

First angle projections and third angle projections are the two main types of orthographic drawing, also referred to as ‘working drawings’. The difference between first and third angle projection is in the position of the plan, front and side views.

In third angle, what you see from the right would be drawn on the right. In first angle, the view from the right would be projected through and drawn on the left. The views in first angle are depicted as if you were looking at an x-ray of the object.

A car drawn in first and third angle projections. Includes top and bottom, left and right side and front views.In a first angle projection the plan view is below the side view, whereas in a third angle projection the plan view is above the side view

First and third angle projections use these symbols on a diagram to indicate which projection they are:

Showing symbols that indicate First Angle and Third Angle drawings.

Orthographic projections have a set of standard lines to show different aspects of the diagram. These lines allow complex shapes to be drawn simply in 2D.

Standard lines showing dark unbroken for outlines, light unbroken for construction lines, dotted for hidden details, dimension arrow intercepted with measurements and broken, dotted as centre lines.Showing the plan, front and side views of a shape using the standard lines and including hidden details.