Choosing The Right End Mills For Aluminum

[Geoffrey Less]

When it comes to working with a milling machine, there are different rules for every material. Aluminum in particular offers a few unique challenges for milling machine operators. When choosing end mills for aluminum, it is important to make sure that you are using the right cutting tools to avoid damaging your tools and your workpiece.

The biggest issue to contend with when milling aluminum is chip production. Machining aluminum is difficult because it is such a soft and flexible metal. As aluminum is machined away, it can form rather large stringy chips. If these chips are not evacuated from the cutting edges, they can be recut into a fine powder. This fine powder can act as an abrasive, marring the surface of your workpiece, or it can heat to the point of friction welding your tool to your workpiece.

Either way, large chips or fine, there are issues that your tool’s design needs to address in order to ensure proper removal of chips. Evacuating these chips is essential for proper operation. The first way to ensure that the chips can be easily removed is to limit the number of flutes being used to make cuts. The more flutes, the smaller the spacing between cuts. Two and three flute end mills are the best option for getting rid of chips easily. The use of four fluted end mills on aluminum regularly cause build up near the base of the end mills.

In addition to choosing the right number of flutes, it is also important to consider the angle of the flutes. Higher flute angles will impart more vertical force on your chips, forcing them away from the base of your end mill. While many end mills have flute angles around 30 degrees, end mills for aluminum tend to feature high helix angles around 35 to 40 degrees or greater. Ensuring that your tools feature those higher helix angles will ensure proper metal removal rates when machining aluminum alloys.

One more factor to consider when choosing an end mill for machining aluminum is the coating used on the tool’s surface. Different coatings offer different properties and, in the case of aluminum tools, the goal is to reduce the friction on the cutter’s surface. Lower friction translates to smoother chip evacuation, which is why many tools will feature a gold colored coating of zirconium nitride(ZrN). This ceramic coating helps lower the tool’s coefficient of friction and increase performance.

If you are looking for reliable end mills for aluminum, you need to check out the options are Online Carbide. They offer three flute ZrN coated end mills with a 37 degree helix angle. These tools are manufactured from solid carbide, which helps to preserve their cutting edges and extend their tool life. If you have any questions about the tools they offer, feel free to reach out to a member of the Online Carbide team by sending an email to [e-mail].