A cube shown with this type of
projection pivots 45º to show two
faces on the projection plane
instead of a single face.
It is then tilted frontward or
backward, allowing three
faces to be observed.
Not intended to give exact
or true view.
Not intended to transmit
sometimes dimension is
Useful when the
instructions to be given to
Hidden lines are not
shown in isometric
axon = axis; metric = measure, in Greek
Axonometric projection is a parallel projection
technique to create a pictorial drawing of an object by
rotating the object on an axis relative to a projection or
Isometric projection is a true representation of the
isometric view of an object.
Isometric view is created by rotating the object 45
degree about vertical axis, and tilting it forward 35
Isometric projection: axes
The 3 axis meet at A,B form equal angles of 120 deg
and they are called Isometric Axes
OA is vertical, OB is inclined at 30deg to the right,
OC is inclined at 30deg to the left
Any lines parallel to these – Isometric Line
Any planes parallel – Isometric Planes
Isometric projection: scale
The tilt causes the edges & planes to become
The projected length is approximately 80% of
the true length.
Draw the isometric projection of a rectangle of 100mm
and 70mm sides if its plane is (a) Vertical and (b)
To draw the isometric projection of a square plane
Draw a line at 30° to the horizontal and mark the isometric
length on it.
Draw verticals at the ends of the line and mark the isometric
length on these parallel lines.
Join the ends by a straight line which is also inclined at 30°
to the horizontal.
There are two possible positions for the plane.
Isometric Projection of Planes
Draw two lines at 30° to the horizontal and mark the
isometric length along the line.
Complete the figure by drawing 30° inclined lines at
the ends till the lines intersect.
(i) The shape of the isometric projection or drawing of
a square is a Rhombus.
(ii) While dimensioning an isometric projection or
isometric drawing true dimensional values only must
*The figure below shows how the cases
can be executed.
Isometric angles & non-isometric lines
Example of producing non-
The position of point Z is
obtained in the isometric
view, by transferring the
distance of X and Y.
Iso-circles and arcs: draw
Drawing isometric circles and arcs using four-centre method.
• To draw an iso-circle, on
left plane, Diameter
(a) Draw centre lines,
vertical & 30deg to left.
(b) Draw (construction line)
20mm “square box”. The
centre lines should
divide each side by half.
(c) Draw straight lines; 1-2 & 1-3 and 2-5 & 2-6.
(d) Point 7 is the intersection between line 1-2 & 2-5, and similarly point 8, 1-3 & 2-6 on the
(e) Set your compass to the distance 7-2, draw an arc with centre at point 7, from point 2 to
point 5. Do the same on the other side.
(f) Set your compass to the distance 1-2, draw an arc with centre (1), from (2) to (3).
(d) (e) (f)
Producing Isometric Projection
Determine front, side &
Try to visualize how the
object looks like.
Start with sketching, do
not draw straight away.
If not sure, start with
sketching an isometric
box, enclosing the
You can label points,
6.3 Sketching isometric cylinder
Start by drawing the bounding box.
The front end of the cylinder is sketched using the
The far end of the cylinder is a partial iso-circle.
Sketch until meeting the tangent with the two straight
ORTHOGRAPHIC MULTI-VIEW PROJECTION ISOMETRIC PROJECTION
How to draw an object containing rounded
Department : Mechanical M-1 (B-Batch).
Created by : Parth P. Prajapati.