Ball End Mills: Which Coating is Right for You?

Ball end mills are the ideal tool for creating contoured shapes in a variety of metals. Unlike square end mills, ball end mills allow the operator to create compound curves in the work material. With their semi-spherical cutting ends, ball end mills have long been popular for making things like valves and fittings that don't allow for sharp machined edges. Today, ball end mills are increasingly being used to produce prosthetic joints such as knees, elbows, and ankles.

The Right Coating = Better ROI on Ball End Mills

When choosing a ball end mill for your specific application, coating is one of the most important considerations. If chosen properly, the correct coating can increase tool life and performance.  So, even though the ball end mill might be more expensive to start, it will last longer and cut better, increasing overall ROI.

There are three basic coatings that work in the vast majority of applications. Those coatings are:

  • AlLTiN - Aluminum Titanium Nitride
  • TiCN - Titanium Carbo Nitride
  • AlCrN -  Aluminum Chromium Nitride

The type of coating needed for milling depends on:

  • the equipment being used
  • the material being milled
  • milling speed
  • milling depth

Using the right coating in each circumstance will increase tool life, improve cut quality, and provide better overall results.


This coating is comprised of aluminum, titanium, and nitrogen. A thin film of the coating is deposited on ball end mills using a physical vapor deposition process. This leaves a thin, tough coating evenly distributed on the tool.

Due to its heat resistance, and increased hardness at high temperatures, ALTiN is perfect for machining:

  • Titanium
  • Tool Steel
  • Alloy Steel
  • Mold Steel
  • Stainless Steel
  • Nickel Alloys
  • Cast Iron
  • Other High-Temperature Materials

As AlTiN heats up during use, a protective layer of Aluminum Oxide forms on the surface of the tool. This layer increases tool hardness, while also lowering thermal conductivity. The result is a tool that holds its edge at high temperatures and transfers less heat into the material being milled. AlTiN coated mills do not require the use of cutting oil or coolant during use.

AlTiN is long lasting when used correctly, and can withstand temperatures of up to 1400 degrees (Fahrenheit). Ball end mills coated with ALTiN leave a smooth, hard finish and allow for higher feed rates.


Composed of titanium, carbon, and nitrogen, TiCN is also deposited via physical vapor. TiCN bonds very well to tool surfaces, preventing chipping, flaking, or blistering during use.

TiCN has high abrasion resistance, making it ideal for cutting materials like:

  • Stainless Steel
  • Aluminum
  • Copper
  • Cast Iron
  • High-Silicon Alloys
  • Other Abrasive Materials

TiCN has a lower high-temperature tolerance than ALTiN. To prevent premature wear, the temperature at the cutting edge must be controlled using coolant or cutting oil.

For non-ferrous and highly abrasivematerials TiCN coatings allow for higher cutting speeds while still leaving a smooth finish. This coating will greatly extend the service life of ball end mills that are used to machine abrasive materials.

Aluminum Chromium Nitride

An incredibly hard mineral composed of aluminum oxide, chromium and nitrogen is  synthetically manufactured. When bonded to tool surfaces, this coating creates a hard cutting surface that is resistant to chipping, flaking, and other erosionunder extreme heat and wear conditions.  Upon request this coating can be added to our Multi-Purpose ball end mills.

With its natural hardness and high heat resistance, AlCrN coating is ideal for machining materials such as:

  • Tool Steel
  • Alloy Steel
  • Mold Steel
  • Other Hardened Materials

AlCrNis one of our newest available coatings. It provides an extremely hard, smooth finish in the milled material. . This coating creates an outstanding workpiece finish, even under high feed rates.

Ball end mills with a AlCrN coating has an extremely long service life, when used correctly. The hard surface, strong bond, and heat resistance ensure that the tool will remain sharp and provide superior cutting for many hours.

A Coating for Every Ball End Mill Purpose

Tool coatings are important for increasing the efficiency and longevity of ball end mills. It is important, however, to match the ideal coating with the intended application. In the proper application, the right coating will provide superior results, while also providing a greater ROI on the tool purchase.

Click here to see the large variety of Ball End Mills Regal has to offer. If you need help finding the right ball end mill for your application be sure to contact us or give us a call at 800-435-2984 and one of our representatives will be happy to assist you.