1
GATE PI 1989
Subjective
+5
-0
The results of machining steel with $$2$$ grades of tool material are given below. For a $$180$$ $$min.$$ Tool life which tool is recommended and why? GATE PI 1989 Machine Tools and Machining - Metal Cutting Question 27 English

If the tool regrinding and changing time is $$15min,$$ the cutting speed for tool $$A$$ $$ahs$$ to be chosen ($$40m/min$$ or $$50m/min$$)

2
GATE PI 1989
Subjective
+5
-0
Calculate the tonnage capacity of the broaching machine required to broach on the hole under the following conditions.
Diameter of the finished hole $$=75mm,$$
rise per tooth $$=0.03mm$$
Tooth pitch $$=10mm,$$
Length of the broach $$=750mm$$
Cutting speed $$=6m/min,$$
specific cutting pressure $$ = 1300 \times {t^{0.4}}\,\,N/m{m^2},$$ (Where $$t$$ is the uncut chip thickness)
If the tool and work handling time is $$0.5min,$$ estimate the production rate per hour
3
GATE PI 1989
MCQ (Single Correct Answer)
+1
-0.3
In $$HSS,$$ the tungsten can be substituted by
A
Chromium
B
Nickel
C
Molybdenum
D
Cobalt
4
GATE PI 1989
Subjective
+5
-0
In a wire drawing operation diameter of $$6mm$$ is reduced in stages to a diameter of $$1.34mm.$$ Assuming ideally rigid plastic material and ideally lubricant condition,
$$i)$$$$\,\,\,\,\,\,\,$$ The minimum number of passes required by assuming max reduction per pass
$$\,\,\,\,\,\,\,\,\,\,\,\,$$ is obtained with $$\mu = 0.2$$ and half die angle as $${6^0}$$. If the flow strength of the
$$\,\,\,\,\,\,\,\,\,\,\,\,$$ material is $$60$$ $$MPa.$$

$$ii)$$$$\,\,\,\,\,$$ The diameter of wire after $${2^{nd}}$$ stage

EXAM MAP