Blueprint Compositions, Continued
Reference
Reference numbers refer to numbers of other drawings. A dash and a
numbers
number show that more than one detail is shown on a drawing. When two
parts are shown in the detail drawing, the print has the drawing number plus
a dash and an individual number. Dashes and numbers identify changed or
improved parts and right- or left-hand parts. Left-hand parts are usually
depicted in drawings. Some drawings use RH or LH for right- or left-hand
parts. Others use even numbers for right-hand drawings and odd numbers
for left-hand drawings. Reference numbers appear in the title block and they
may also appear within the drawing near the parts they identify. Some
reference numbers use a leader line to show the drawing and dash number of
the part. Others use a 3/8-inch diameter circle around a dash number with a
leader line to the part.
Figure 1-38 is an example of reference numbers.
Figure 1-38.—Reference number location.
1-50
Continued on next page
