Special End Mills, Tapered End Mills, Corner Rounding, Diamond Coated, Roughing, And Single Flute

Tool and die, injection mold making and precision machine shops use a huge variety of end mills to cut the many tooling components they need. Some of the special end mills, such as tapered end mills, corner rounding, diamond coated, roughing and single flute play a very important role in the process.

The more common cutters, such as indexable end mills, face mills, slotting cutters, solid carbide end mills, and insert cutters do the bulk of the work in a typical tool shop, but these tapered end mills have a very important place as well.

In the past, before the days of CNC machining centers, the tapered end mill was responsible for adding draft to molding surfaces and relieving fitted blocks. Most mold core and cavity finish work is either done in the sinker EDM, wire EDM or high speed milling machine. Nevertheless, many shops use tapered end mills because they are quick, reliable and easy to use.

Corner rounding cutters are similar. Used to be that all the blocks had a radius at the corner to fit into the mold plate pocket. Most blocks are cut on the CNC, such as a Deckel-Maho HSC 20, HSC 55,or HSC 75 5 Axis machining center.

Many other machine tool manufacturers produce high quality machines for the trades, including Makino, Sodick, Mitsubishi, Haas, and Droop and Rein. The tapered end mills play an important role , along with the conventional carbide cutters.

Yet the corner rounding tool still gets plenty of use in many shops around the world. Often it is much faster to simply mount the block in a vise and mill the corner, rather than create a CAD file, create a CAM file, set it up, program it and finally cut it.

Mold repair is a good example of using these special cutters. Many times the toolmakers must make a single flute end mill to do some delicate work in a core or cavity. The Deckel grinder SO is very common and useful for these one-of-a-kind operations.

These tools used to be very common and every toolmaker had a little box of tapered end mills, radiused, bull-nosed, and sometimes unknown geometries. These came in very handy for cutting the details required, but those days are long gone, thankfully.

Roughing cutters have largely gone the way of the other specialties, yet they still have a role to play. The old corn cob type could certainly do some serious cutting on the Bridgeport, with the operator cranking away, coolant bottle in hand. Many pockets and insert blocks were roughed out this way, and many guys had little red marks all over their hands and arms to prove it.

Today’s roughing cutters are largely carbide insert cutters. Companies such as Iscar, Ingersoll, Sandvik and Kennametal all carry extensive lines of these amazing beasts. Some have dozens of inserts placed in strategic locations to maximize metal removal rates.

Diamond coated tapered end mills are amazing in their ability to cut very difficult hardened steels, such as D-2 and H-13. The speed and feeds, as well as the dimensional accuracies and surface finishes are astounding. For high speed machining operations, this is a common choice of tooling.