All End Mills are NOT Created Equal

As an end mill manufacturer that takes extreme pride in what we do, there is nothing that upsets us more than being told by a buyer that they are going with a competitive product because the other end mill is cheaper.  We can talk about our quality until we are blue in the face, but I feel the word “quality” is thrown around so often that I don’t think it really means anything anymore.  So in this article, I will not “talk” quality, but rather “show” quality.

Shown below, are three different .040″ Diameter 2FL Ball End Mills manufactured by three different manufacturers. One is ours (Advanced Tool) and two are other USA manufacturers.  I will let you be the judge, do all three look the same to you?  This is a typical scenario when purchasing a standard off-the-shelf end mill from one manufacture vs another.  You can visually see that they are very different from one another.

Good end mill geometry

Advanced Tool – .040″ 2FL Ball End Mill

This end mill is made with the proper web thickness and gash (referring to the center of the end mill). You can also notice a slight “S” curve to the gash (running from the top of the picture to the bottom), this is referred to as a helical gash.  A helical gash on a ball end mill is an advanced geometry design. This design is used so that less of the cutting edge comes in contact with the part at one time, causing less pressure to the cutting edge. This end mill is going to give you maximum performance and tool life.



poor end mill geometry, thin web

USA made Competitor End Mill #1 – .040 2FL Ball End Mill

If you look at the center of the end mill, you can notice a paper thin portion of the end mill, that is the web.  This web is far too thin for the end mill to perform properly.  That section is too weak and will ultimately break during use. This end mill also has a poor finish (those small lines running horizontal on the cutting edge should not be as visible as they are).



poor end mill geometry - thick web

USA made Competitor End Mill #2 – .040 2FL Ball End Mill

Again, looking at the center of the end mill, you can see that this web is much thicker or fatter than the one above. This is also poor geometry.  When the web of an end mill is too thick, there is a large dead area that won’t cut. This causes more pressure on the end mill resulting in premature failure and/or breakage.  You can also notice that there is less of an “S” curve to the gash, this is referred to as a straight gash.  A straight gash will need to work harder during use and will dull faster.



So you see, all end mills are not created equal, in fact there is a big difference. You may be thinking that this can’t be common practice, but unfortunately it is.  The competitive brands shown above are popular well known brands.

At the end of the day, it’s all about results.  You should see consistent results from one end mill to the next, every single time.  If you are not getting the same number of cuts, same number of holes, or same number of parts per end mill every time, then you need to question the quality of the mill you are using.  This will save you a tremendous amount of money on an annual basis. You will need to purchase far more poor geometry end mills to achieve the same results of one end mill with the proper geometry and this is adds up quicker than you realize.  It is critical to determine cost by measuring the number of parts per end mill, not by the price of the end mill itself.  Many manufacturers pump their products out the door as fast as they can to keep the costs as low as possible.  It takes a tremendous amount of effort to ensure every single end mill is made the right way, every single time.  Now go look at your end mill geometry and tell us what you see.