DRILLING - Quiz

1) What is the drill hole size for 16 mm reamer?

15.75 mm 15.50 mm 14.65 mm 16 mm

2) What is the size of drilled hole for reaming, Dia 10 mm?

8.5 mm 9.75 mm 10.00 mm 10.25 mm

3) Why drilled holes are over size than drill dia?

Feed ratio is more Cooling is in effective Insufficient clearance angle Unequal length of cutting edge

4) What is the counter sink angle of chamfering in the end of drilled hole for threading?

75 Degree 80 Degree 90 Degree 120 Degree

5) Why centre screw is provided in the die stock?

To tighten the die To adjust the depth of cut To adjust the dia of internal thread To adjust the dia of external thread