Machine Drawing

238 Machine Drawing

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d:\N-Design\Des15-2.pm5

DRAWING EXERCISES

15.1 Calculate the maximum and minimum limits for both the shaft and hole in the following; using

the tables for tolerances and name the type of fit obtained:

(a) 45H8/d7 (b) 180H7/n6 (c) 120H7/s6

(d) 40G7/h6 (e) 35 C11/h10

15.2 The dimensions of a shaft and a hole are given below:

Shaft, Basic size = 60mm and given as 60 – 0.020

Hole, Basic size = 60mm and given as 60 – 0.005

Find out:

(a) Tolerance of shaft (b) Tolerance of hole (c) Maximum allowance

(d) Minimum allowance (e) Type of fit

15.3 A schematic representation of basic size and its deviations are given in Fig. 15.19. Calculate the

following in each case for a shaft of 50 mm basic size:

(a) Upper deviation (b) Lower deviation (c) Tolerance

(d) Upper limit size (e) Lower limit size

+24

–5

(a) (b)

–7

0

+30

+10

(c)

–20

–40

+40

0

(e)

(d)

Fig. 15.19

15.4 A schematic representation of basic size and its deviations are given in Fig. 15.20. Identify them.

Zero line

C

E D

B A

Fig. 15.20

15.5 A 30mm diameter hole is made on a turret lathe to the limits, 30.035 and 30.00. The following

two grades of shafts are used to fit in the hole:

(a)φ29.955mm and 29.925mm, and (b)φ30.055mm and 30.050mm.

Calculate the maximum tolerance, clearance and indicate the type of fit in each case by a sketch.