3- Twist Drill - 3: Shanks
|Twist drills have a variety of body and cutting configurations to accommodate various machines and materials. The most common is the straight and the tapered shank. Although there are other tapers the Morse taper is the most common.|
|The straight shank configuration can be the same diameter overall or can be ground to a smaller diameter in order to fit a smaller Jacobs drill chuck that is unable to take the size of drill being used. The straight shank can also be fit to taper shank adapter. CNC machine tool holders use the straight shank drill, tapered shanks are used mostly on conventional machines.
The tapered shank drill fits firm and accurately into the tailstock of a lathe or a spindle of a drill press. Caution should be taken that only like tapers are used. Tapers that do not match can result in damage to both the drill and the machine's holder and result in an unstable tool.