After the work is centre-drilled and cut off to length, it must be finally Countersunk, so as to provide ample bearing area for the lathe centres.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
1192, when the half-round reamer will, if the work be rigidly held while being Countersunk, act as a cutting tool.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
The taper bolts should be of steel, but those with Countersunk heads may be of iron.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose