Engineering Drawing for Manufacture phần 4 docx

ISO drawing rules 4b

V V

~W movement

F _ .

.Item List

.10 .1 Plate Screw

9 .1 Plate

8 4 Insert Screws

7 .1 Tommy Bar

6 ,1 Jaw Clamp Screw

5 1 Bush Screw

.4 1 Bush

3 1 Movable Jaw

2 2 Hardened Inserts

1 .1 Body

PartNo, I~" De~'dped~

VICE ASSEMBL Y DRAWING

Not to scale -(~ [~]-

Figure 3.1 Assembly engineering drawing of a small hand vice

Figure 3.2 is a third-angle orthographic projection 'detail'

drawing of the movable jaw (part number 3). It gives all the infor￾mation necessary for the part to be manufactured. The outline is

drawn in thick (or wide) lines whereas additional information (e.g.

hidden detail or section hatching) is drawn in thin (or narrow) lines.

The thick lines are deliberately drawn so that shape and form

[jump' out of the picture. With regard to the front elevation, the

'equals' sign at either end of the centre line shows that it is symmet￾rical about that centre line. The 16mm wide tongue is thus centrally

positioned in the front elevation and there is no need to dimension

its position from either side. There are further outcomes from this

symmetry. Firstly, both underside surfaces that contact the body (as

shown by thick chain dotted lines) are to be polished such that the

average surface finish (Ra) is less than 0,2urn. Secondly, the

counter-bored 5mm diameter holes are identical. The right-hand

elevation is a section through the centre of the jaw but nothing tells

you this. This is the designer's decision of how much to include in

the drawing, called 'draughtsman's licence'. The side elevation

shows that there is a vertical threaded hole in the base. The various