The usual value of the helix angle of a drill is

A. 20°

B. 30°

C. 45°

D. 60°

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  1. The ductile materials, during machining, produce
  2. The in-feed grinding is used to
  3. Gears can be best produced on mass production by
  4. High speed steel drills can be operated at about _________ the speed of high carbon steel drills.
  5. Fixtures are used
  6. Green sand mould indicates that
  7. A __________ grinding wheel is used to grind soft materials.
  8. The high cutting speed and large rake angle of the tool will result in the formation of
  9. A type of welding flows, which is the result of a perfect proportion and mixture of acetylene and oxygen…
  10. When the metal is removed by erosion caused by rapidly recurring spark discharges between the tool and…
  11. The tool life in case of a grinding wheel is the time
  12. The grinding wheel speed (surface speed in m/min) usually varies from
  13. Which of the following statement is wrong about ultrasonic machining?
  14. The grade of grinding wheel depends upon
  15. In a shaper
  16. What is the type of welding defect caused due to poor manipulation of weld rod or a dirty joint called?
  17. The type of reamer used for reaming operation in a blind hole, is
  18. Ultrasonic machining is best suited for
  19. A left hand tool on a lathe cuts most efficiently when it travels
  20. The broaching operation in which either the work or the tool moves across the other, is known as
  21. In gear hobbing
  22. In _________ operation, the cutting force is maximum when the tooth begins its cut and reduces it to…
  23. In an orthogonal cutting, the depth of cut is halved and the feed rate is double. If the chip thickness…
  24. A dynamometer is a device used for the measurement of
  25. Glazing in grinding wheels can be decreased by
  26. An important geometrical quantity in the cutting of metals which can be used as a criterion for machinability…
  27. The cutting speed for drilling copper with high speed steel drills varies from
  28. In a single point tool, the angle between the surface of the flank immediately below the point and a…
  29. The height of each tooth of a broach is
  30. Larger than 15° side cutting edge angle