Correct option is A
In a drilling machine,
drill chucks are fitted onto the spindle using an
arbor (also known as a taper shank or a Morse taper). The arbor is designed to fit the tapered hole in the spindle and the drill chuck, ensuring a secure and precise fit.
Arbor (Correct Answer):
An arbor is a tapered shaft used to mount the drill chuck onto the spindle.
The taper (commonly Morse taper) fits into the corresponding tapered hole of the machine spindle.
The friction created by the tapered surfaces holds the chuck firmly in place. This method is widely used for its reliability and ease of alignment.
Drift: A
drift is a wedge-shaped tool used to
remove the taper (arbor) from the spindle.
It is inserted into a slot in the spindle to dislodge the arbor, making it useful for disassembly, not assembly.
Knurled Ring: A
knurled ring is found on some chucks for
manual tightening of the chuck jaws, but it is not related to fitting the chuck onto the spindle.
Pinion & Key: The
pinion and key mechanism is used to open and close the chuck jaws to hold the drill bit but does not secure the chuck to the spindle.
