1
GATE PI 1990
+5
-1.5
A parting tool has a ground front clearance angle of $${6^0}$$ and the back rake angle of $${10^0}$$. The tool, by mistake, was set $$1.5$$ $$mm$$ above the line of centers while machining a job of $$50$$ $$mm$$ out-side diameter.

The diameter of the job at which, while parting, the tool will start rubbing

A
$$35mm$$
B
$$28.7mm$$
C
$$57.4mm$$
D
none
2
GATE PI 1990
Subjective
+5
-0
The following data apply to machining a part on turret lathe and a general purpose lathe

The setup cost and the cost for special tooling on the turret lathe would be $$Rs.3000/-.$$ These costs are negligible on the general purpose lathe. Calculate the batch seize which justifies the use of turret lathe.

3
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
4
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?

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

GATE PI Subjects
Engineering Mechanics
Theory of Machines
Machine Design
Fluid Mechanics
Thermodynamics
Casting
Joining of Materials
Metal Forming
Machine Tools and Machining
Metrology
Industrial Engineering
EXAM MAP
Medical
NEET