Screwed-shank cutters

Figure 11.11. Milling chuck for screwed-shank cutters...

With the aid of a sketch show how a screwed shank cutter is held in a milling chuck. 

Cutters having screwed shanks are mounted in a special chuck, shown in Fig. 11.11. The collet, which is split along the length of its front end and has a short taper at the front, is internally threaded at its rear end. Collets of different sizes are available to suit the shank diameter of the cutter used. The collet is inserted into the locking sleeve and the assembly is screwed into the chuck body until the flange almost meets the end face of the body. 

There are many different types of milling cutters available, and for convenience they can be classified according to the method of mounting those with a central hole for mounting on an arbor, those with a screwed shank for holding in a special chuck and the large facing cutters which mount directly on to the spindle nose. 

Countersink cutters, Fig. 8.13, made from high-speed steel, are used to cut a large chamfer of the correct angle, usually 90°, as a seating for countersink-head screws. Countersinks should be run at a fairly slow speed to avoid chatter. They are available with parallel and taper shanks. 

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