554. Best coolant and lubricant for aluminium is
A.Water soluble oils or sulphur based and mineral oils
B.Mineral and fatty oils or soluble oils
C.Soluble oils
D.Dry

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555. Non-ferrous cast tool steel operates best at
A.Cold temperatures
B.High temperatures of 500°C
C.Temperature has no-effect
D.Elevated temperatures of 825°C and lose efficiency if operated at cold temperature

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556. Carbide tool bits are ground by following type of grinding wheel
A.Aluminium oxide
B.Silicon carbide
C.Diamond
D.Cobalt

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557. Powder metallurgy techniques are used in the production of
A.High carbon tool steels
B.HSS tools
C.Tungsten carbide tools
D.Twist drills

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558. Which of the following abrasives is the hardest
A.Al2O3 (Aluminium Oxide)
B.Diamond
C.Si C (Silicon Carbide)
D.CBN (Cubic Boron Nitride)

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559. The hardness of carbon tool steels is increased when alloyed with
A.Tungsten
B.Chromium and vanadium
C.Silicon
D.Manganese

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560. High speed steel tool material contains carbon
A.0.6-1.0%
B.2-4%
C.4-6%
D.6-10%

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