77) When threading a blind hole, the third (finisher) tap is used

to thread the hole with full threads up to the bottom

to start the threads

after the first (rougher) tap

to form the threads easily

Answer is:

to thread the hole with full threads up to the bottom

45 Degree to the centre line of the file

60 Degree to the centre line of the file

75 Degree to the centre line of the file

80 Degree to the centre line of the file

Answer is:

Parallel reamer

Adjustable reamer

Expansion reamer

Chucking reamer

Answer is:

Explanation:

A short reamer with an axial hole used an arbor or mandrel is called as chucking reamer.

H.S.S.

Carbide steel

Diamond

Cast steel

Answer is:

Eye level

Shoulder level

Elbow level

Arm level

Answer is: