Page 138 - CITS - ED - Mechanical

ENGINEERING DRAWING - CITS

Fig 4 Fig 5

Fig 6 Fig 7

Domed Cap nut (IS:7790): Hexagon nut with a hemispherical top. Its function is similar to cap nut. It is available
in 11 sizes from M6 to M24 diameter bolts/screw. They are made of steel, brass or aluminum alloy. It prevents
corrosion and leakage of fluids from the threads. (Fig 8)

Washer: It is a cylindrical thin disc with a hole in the centre. Washer helps to provide smooth bearing surface between
the nut and the part on which it is used. There by it prevents the nut corners from cutting into the metal. (Fig 9)
There are plain washers (IS:2016:5370) and spring washers (IS:6755,3063,6735).
Plain washers are available from basic hole size 4 to 155 mm dia to suit bolt/screw size from M 1.6 to M 150 mm.
One face is chamfered at 45 While spring washer exerts pressure on the nut tightening and keeps the thread
o.
gripped on the thread.

Fig 8 Fig 9

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CITS :Engineering Drawing (Mechanical) - Exercise 8