Figure 3-1.-Blueprint Title blocks: (A) Naval Ship Systems Command

Figure 3-1.-Blueprint Title blocks: (A) Naval Ship Systems Command; (B) Naval Facilities Engineering Command.

Reference Numbers

the drawing and dash number and carry a leader line to

the part; others use a circle, 3/8 inch in diameter around

Reference numbers that appear in the litle block

the dash number and carry a leader line to the point.

refer to the number of other blueprints. When more than

A dash and number are used to identify modified or

one detail is shown on a drawing, a dash and a number

improved parts and to identify right-hand and left-hand

are frequently used. For example, if two parts are shown

parts. Many parts on the right side of a piece of

in one detail drawing, both prints would have the same

equipment are identical to the parts on the left sidein

drawing number, plus a dash and an individual number,

reverse. The left-hand part is usually shown in the

such as 8117041-1 and 8117041-2.

drawing.

In addition to appearing in the Title block, the dash

Above the Title block on some prints, you may see

and number may appear on the face of the drawings near

the parts they identify. Some commercial prints show

a notation such as 159674 LH shown; 159674-1 RH

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