How Are End Mills Mounted

In our previous article, we gave information about end mills. In this article we’ll cover topics like how end mills are mounted and what they’re mounted with.

Mounting End Mills

End mills and similar cutters with a cylindrical shank are mounted into the spindle nose using collets, fitted into a collet adapter, and pulled in just as with short arbor shafts.

What Is a Collet Chuck Assembly? Mounting an End Mill with a Collet Chuck Assembly

Small-diameter shank-type milling cutters (end mills) are mounted using a collet-chuck (adapter) assembly.

Collets are made in various sizes and are identified by taper numbers. They’re generally used for clamping diameters within a specific range. These sizes are made from 1 millimeter to 16 millimeters, and from 5 mm to 25 mm. Larger diameters are also used, though less commonly. Collets come as a set but each performs the clamping through its own adapter.

Points to Pay Attention to When Mounting End Mills

Collet wrench (crescent wrench)

Collet adapter – chuck

First, a collet matching the diameter of the milling cutter to be mounted is selected and placed inside the adapter nut.

Holding the collet in one hand and the adapter nut in the other, as shown in the figure, you’ll hear a click as they’re seated together.

Then, the adapter nut is fitted onto the collet chuck. At this stage, do not overtighten the adapter nut.

In the next step, the milling cutter is placed into the collet. The nut is tightened all the way.

use of the collet wrench crescent wrench

The adapter nut is then tightened with the collet wrench.

Then, if there is a cutting tool such as a surfacing cutter mounted on the vertical head, the arbor pull nut is loosened and it’s removed as shown in the picture. The collet chuck is mounted the same way. Before doing this, it’s recommended to set the machine to a low speed.

Removing an End Mill from the Collet Adapter

When we’re finished with the end mill and want to remove it, the chuck nut is loosened with the wrench, removed from the end mill socket, and then the collet itself is removed from the adapter. If done in the opposite order, the collet can get stuck in the socket.

Keep in mind that collets are very precise and will break if dropped on the floor. Collets are not sold individually.
Before clamping, the collet and chuck socket should be thoroughly cleaned. Otherwise the cutter will run out.