687. Ceramic tips are prepared from
A.Tungsten powder
B.Carbon powder
C.Aluminium oxide powder
D.Silicon carbide powder
688. Which of the following are cast alloys containing tungsten and chromium carbides in a matrix of cobalt and chromium
A.Mechanites
B.Tungsten carbides
C.Bakelites
D.Stellites
689. Carbide tips are fixed to the shanks of cutting tools by
A.Forging
B.Brazing
C.Welding
D.Soldering
690. The most wear-resistant grade of carbide used for cutting tools is the straight
A.Iron carbide
B.Calcium carbide
C.Tungsten carbide
D.Nickel carbide
691. With increase in cutting speed, the finish
A.Improves considerably
B.Improves slightly
C.Remains same
D.Gets poor
692. When turning a long shaft on a lathe, its bending can be prevented by
A.Running the shaft at low speed
B.Using steady rest
C.Using low depth of cut
D.Using sturdy machine
693. In oblique cutting system, the chip thickness is
A.Maximum at middle
B.Maximum at sides
C.Minimum at middle
D.Uniform throughout
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