There is a wide variation in sizes for engineering objects.
Some are very large (eg. Aero planes, rockets, etc) Some are vey small ( wrist
watch, MEMs components)
There is a need to reduce or enlarge while drawing the objects on paper. Some objects can be drawn to their actual size. The proportion by which the drawing of aan object is enlarged or reduced is called the scale of the drawing.
There is a need to reduce or enlarge while drawing the objects on paper. Some objects can be drawn to their actual size. The proportion by which the drawing of aan object is enlarged or reduced is called the scale of the drawing.
Definition
A scale is defined as the ratio of the linear dimensions of the object as represented in a drawing to the actual dimensions of the same.
A scale is defined as the ratio of the linear dimensions of the object as represented in a drawing to the actual dimensions of the same.
· Drawings
drawn with the same size as the objects are called full sized drawing.
· It is not
convenient, always, to draw drawings of the object to its actual size. e.g.
Buildings,
· Heavy
machines, Bridges, Watches, Electronic devices etc.
· Hence
scales are used to prepare drawing at
o Full size
o Reduced size
o Enlarged size
BIS Recommended Scales are shown in table 1.
Intermediate scales can be used in exceptional cases
where recommended scales can not be applied for functional reasons.
