12 Machine Drawing
dharm
d:\N-Design\Des2-1.pm5 Seventh Print
DRN
CHD
APPD
NAME DATE MATERIAL TOLERANCE FINISH
170
PROJECTION LEGAL
OWNER
TITLE
SCALE IDENTIFICATION NUMBER
65
Fig. 2.3 Details in title block
Trimming mark
12 3
A
456
A
B
C
D
12 3 4 5 6
Metric reference graduation
Orientation mark
Frame
Centring mark
Drawing space
D Title block
Edge
Minimum width
(20 mm for A0 and A1
10 mm for A2, A3 and A4)
Grid reference Border
Fig. 2.4 Drawing sheet layout
2.2.5 Centring Marks
Four centring marks may be provided, in order to facilitate positioning of the drawing when
reproduced or microfilmed. Two orientation marks may be provided to indicate the orientation
of the drawing sheet on the drawing board (Fig. 2.4).
2.2.6 Metric Reference Graduation
It is recommended to provide a figure-less metric reference graduation, with a minimum length
of 100 mm and divided into 10 intervals on all the drawing sheets (Fig. 2.4) which are intended
to be microfilmed. The metric reference graduation may be disposed symmetrically about a
centring mark, near the frame at the border, with a minimum width of 5 mm.
