Machine Drawing

Principles of Drawing 19

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A BCDEFGHIJKLMN

OPQRS TUVWX Y Z

bcde fghkl mn op

qr stuvw x yz

[( ;"–=+× %& [(

(^012) 3 45 6 789 I V X

75°

c i

Fig. 2.9 Inclined lettering

Table 2.7 Lettering B (d = h/10)

Characteristic Ratio Dimensions, (mm)

Lettering height h (10/10)h 2.5 3.5 5 7 10 14 20

(Height of capitals)

Height of lower-case letters c (7/10)h — 2.5 3.5 5 7 10 14

(without stem or tail)

Spacing between characters a (2/10)h 0.5 0.7 1 1.4 2 2.8 4

Minimum spacing of base lines b (14/10)h 3.55 7 10142028

Minimum spacing between words e (6/14)h 1.5 2.1 3 4.2 6 8.4 12

Thickness of lines d (1/10)h 0.25 0.35 0.5 0.7 1 1.4 2

Figures 2.9 and 2.10 show the specimen letters of type A, inclined and vertical and are

given only as a guide to illustrate the principles mentioned above.

2.6 SECTIONS

In order to show the inner details of a machine component, the object is imagined to be cut by

a cutting plane and the section is viewed after the removal of cut portion. Sections are made by

at cutting planes and are designated by capital letters and the direction of viewing is indicated

by arrow marks.