Abrasives are not used in

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 $$50m/min$$)

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

In $$HSS,$$ the tungsten can be substituted by