Geometry of Twist Drill

Q. The rake angle in drill

1. Increase from centre to periphery
2. Decreases from centre to periphery
3. Remains constant
4. Is irrelevant to the drilling operation

Q. Consider the following statements:
The helical flute in a twist drill provides the necessary
1.Clearance angle for the cutting edge.
2. Rake angle for the cutting edge.
3. Space for the chip to come out during drilling.
4. Guidance for the drill to enter into the workpiece.
Which of the statements given above are correct?

1. $1$ and $2$
2. $2$ and $3$
3. $3$ and $4$
4. $1$ and $4$

Q. Helix angle of fast helix drill is normally

1. $35$ deg
2. $60$ deg
3. $90$ deg
4. $5$ deg

Q. The purpose of helical grooves in a twist drill is to
1. Improve the stiffness
2. Save a tool material
3. Provide space for chip removal
4. Provide rake angle for the cutting edge
Select the correct answer using the codes given below:

1. 1 and 2
2. 2 and 3
3. 3 and 4
4. 1 and 4

Q. A blind hole is better tapped with a tap having

1. right hand flutes
2. left hand flutes
3. straight flutes
4. no flutes