Counter-boring is the process of enlarging the end of an existing hole to accommodate the head of socket screw.
51) The process of enlarging the end of an existing hole to accommodate the head of socket screw is called
Related Cutting Tools MCQ - Machinist(Set-1) with Answers
Countersinking is an operation of bevelling the end of a drilled hole. The tool used is called a countersink.
The working surface of the job and the bottom surface of cutting edges of chisel
For conduit and other thin tubing, sheet metal work etc. use a 0.8 mm pitch.
For soft materials such as bronze, brass, soft steel, cast iron, heavy angles etc. use a 1.8 mm pitch blade.