ENGINEERING SCALES
It is not always possible or convenient to draw drawings of
an object to its actual size. For instance, drawings of very big objects like
buildings, machines, etc., cannot be prepared in full size because they would
be too big to accommodate on the drawing sheet. Drawings of very small objects
like precision instruments, namely, watches, electronic devices, etc., also
cannot be prepared in full size because they would be too small to draw and to
read.
Special Unusual Scales: When you require to make measurements other than
those given by the set of standard scales MI to M8, Special Unusual Scales have
to be constructed. A convenient scale is always chosen to prepare the drawings
of big as well as small objects in proportionately smaller or larger sizes. So,
the scales are used to prepare a drawing at Full Size, Reduced Size or Enlarged
Size.