Fig. 1955.
[Fig. 1955] (from The American Machinist) represents an arbor, having a cone at a, so that the cutter bore being coned to correspond, the cutter will run true, notwithstanding that it may not fit the stem b. It is obvious, however, that the nut and washer must be made quite true or the cutter will be thrown out of line with the arbor axis and therefore out of true, and also that such an arbor is not suitable for cutters of a less width of face than the length of the cone a.
Fig. 1956.
Shank cutters that have parallel shanks as in [Fig. 1928] should have their sockets eased away on the upper half of the bore as denoted by the dotted arc d in [Fig. 1956], which will enable the cutter shanks to be made the full size of the socket bore proper, and thus run true while enabling their easy insertion and extraction from the socket. Or the same thing may be accomplished by leaving the socket bore a true circle fitting the cutter shanks in tight, and then easing away that half of the circumference that is above the centre line c in the figure. It is preferable, however, to ease away the bore of the socket, which entails less work than easing away the shanks of all the cutters that fit to the one socket. When the cutter is held in a socket of this kind it allows it to be set further in or out, to suit the convenience of the work in hand, which cannot be done when the cutter has a taper shank fitting into the coned bore of the machine spindles.
Fig. 1957.
It is obvious that when the cutter requires to pass within the work, or cut its way, as in the case of milling out grooves, a nut cannot be used; hence, inch cutters are driven by a key as usual, but secured by a screw, as in [Fig. 1957], which is from the pen of John J. Grant, in The American Machinist.