Coatings: Benefits and Uses

Coatings remain one of the most misunderstood elements of cutting tools. Sometimes viewed as another method by which manufacturers sneak a few more bucks out of their customers the benefits are often snubbed by end users. But maybe there is something to these coatings. Lets take a closer look.

There are many coatings available for end mills and other cutting tools and this may be one of the reasons coatings are so misunderstood. The biggest benefit to coatings is that they reduce friction and keep the tool cooler. The result is longer lasting tools and typically better surface finish. Here is a list of the most popular: Titanium Nitride, Titanium Carbo Nitride, Zirconium Nitride, Titanium Aluminum Nitride, Aluminum Titanium Nitride and Diamond Coating. I'll discuss the most popular of these.

Titanium Nitride (TiN) - Known on the Toolinghouse website as coating suffix -01. TiN consists of a very hard coating on the surface of the tool. It has outstanding resistance to wear as it reduces friction and prevents galling. Technically speaking Titanium Nitride is a PVD process with an approximate hardness of 2400HV, Rc86.

Titanium Carbo Nitride (TiCN) - Known on the Toolinghouse website as coating suffix -02. TiCN consists of an extremely hard coating on the surface of the tool. It also has outstanding resistance to wear and reduces friction and prevents galling. Titanium Carbo Nitride is a PVD process with an approximate hardness of 3000HV, Rc94.

Titanium Aluminum Nitride (TiALN) - Known on the Toolinghouse website as coating suffix -04. TiALN consists of an extremely hard coating on the surface of the tool. It has outstanding resistance to wear and reduces friction and prevents galling. TiALN forms an aluminum oxide layer at high speeds and elevated temperatures. Titanium Aluminum Nitride is a PVD process with an approximate hardness of 2600HV, Rc89. Simply stated: TiALN needs heat to work properly.

I highly recommend the use of coatings on carbide end mills. I won't say that it is a waste to use an uncoated sub-micrograin carbide end mill because sometimes it is all you need but the benefits of using one with the proper coating are self-evident. This holds true especially in hard materials or fast speeds where heat is being generated. Notice our QuickKut VH Series End Mills that are specifically designed to machine tough materials are only offered coated. I won't sell one uncoated. In fact, as I typically do, here is another anouncement that you will hear first on the blog. We have designed a new coating that we call 1122 (pronounced eleven-twenty-two) for our VH Series End Mills. It will be available soon and I'll give you more details about it later. I will say that in tests we have seen increased tool life of 50%-400% with this coating.

So, ultimately it is your choice as to whether you use a coated or uncoated carbide end mill. If you are not generating heat through the cutting of hard materials or with high speeds and feeds you can probably get away with uncoated. But for most CNC applications and definately those applications with hard materials (Titanium - Stainless and similar) try a TiALN coated end mill. Soon you'll be able to try our new exclusive 1122 coating.