The following data refers to an orthogonal machining of mild steel with a single point $$HSS$$ tool. Rake angle of tool $$ = {10^ \circ },$$ uncut chip thickness $$=0.3mm,$$ width of cut $$=2.0mm,$$ single plane shear angle $$ = {36^ \circ },$$ shear strength of mild steel $$=450$$ $$MPa,$$ using Merchants analysis

The coefficient of friction between the chip and tool will be

A cylinder of $$25mm$$ diameter and $$100mm$$ length is turned with a tool, for which the relation $$V{T^{0.25}} = 55$$ is applicable. The cutting velocity is $$22m/min.$$ For a tool feed of $$0.046$$ $$mm/rev,$$ the number of tool regrinds required to produce $$425$$ cylinders is

Match list - $${\rm I}$$ (machine tool) with list - $${\rm I}$$$${\rm I}$$ (machine tool part)

Which one of the following is not a synthetic abrasive material