Aside from steel and iron, aluminum is one of the most widely used metals on the planet. This comes as no surprise given that it is the most abundant metal in the Earth's crust. Aluminum is softer and lighter than the majority of other commercially available metals. These characteristics may make aluminum appear to be extremely easy to work with, but it actually presents a unique set of challenges when compared to harder materials like steel. There are several factors to consider when looking for the best end mills for aluminum.
You're probably thinking that a soft metal should be easier to work with, and you'd be correct. Unfortunately, because aluminum is so easy to cut with high-speed tools, it does not form hard chips like steel. Instead, when aluminum is milled, it produces long chips due to the softness of the material. Because these chips are so light, they can cling to your cutting tool rather than being evacuated from the cutting area properly. If aluminum chips are not successfully evacuated, they can build up and damage end mills.
The best end mills for aluminum alloys have specially designed flutes to help eject the aluminum chips, ensuring proper chip evacuation. A typical end mill will have a helix angle of about 30 degrees (the angle between the tangent of the flute's cutting edge and the tool's central axis). When working with aluminum, a high helix angle in the 35 to 45 degree range is preferred. When CNC machining aluminum, this steep helix angle will provide a higher metal removal rate.
Along with a higher helix angle, you should consider the number of flutes. You'll want to look for lower flute counts so that your flutes are wide enough to easily evacuate chips. Most aluminum end mills will have only two to three flutes. Higher flute end mills are inefficient, and soft aluminum can easily cake around the base of your end mill at high speeds and feeds, potentially damaging your workpiece and end mill.
If you want the longest tool life possible, go with a solid carbide end mill. While steel tools can cut aluminum, high performance carbide tools are more wear resistant and have better edge retention. Many aluminum end mills are also zirconium nitride treated. This golden-colored coating not only provides a hard and erosion-resistant outer shell, but it also reduces end mill friction, making chip expulsion easier.
If you want to find the best end mills for aluminum from a reputable American manufacturer, you should look into the tools available at Online Carbide. They sell aluminum cutting three flute solid carbide end mills. These end mills have 37 degree helix angles and are available in a wide range of sizes. They coat their aluminum end mills with ZrN to add strength. All of their end mills and drill bits are all precision machined on advanced 5 axis CNC grinders, producing tools that meet extremely precise standards.
To view their entire inventory, check out their online store. Unlike many tool manufacturers, Online Carbide does not use middlemen, which means you can save a lot of money with their manufacturer-direct pricing. If you have any questions about their tools or the ordering process, you can reach out to a member of their team by sending an email to email@example.com.