Before turning on your CNC machine, selecting the proper end mill might be a difficult process. Every end mill manufacturer will provide you with the right product to meet your requirements. There are several considerations to follow, but first, know about the end mill.
What exactly is an end mill, and how does it differ from a drill bit? As terminologies are misunderstood, this is a common query, but the simple answer is no! An end mill can cut laterally into the material and create slots or profiles, whereas a drill bit plunges directly into the material and generates holes only. Most end mills cut from the center, which means they may also plunge into the material, making them significantly more versatile than drill bits.
End mills are distinguished by their kind, several flutes, and material besides these geometric characteristics. In a traditional catalog, the end mill described above might be characterized as:
Each of these characteristics has a direct impact on how the end mill behaves during machining and the cutting capabilities in terms of performance and shape.
End mills come in as many varieties as cutting operations:
Here are some most common ones:
The most popular type of end mill is the square end mill. This is used for a variety of milling tasks, such as slotting, profiling, and plunge cutting.
These have slightly rounded corners that help distribute cutting forces uniformly and improve the life of the end mill. They can make grooves with a flat bottom and slightly rounded inside corners.
During heavy operations, roughing end mills are used to remove significant volumes of material. Their design reduces or eliminates vibration, but results in a harsher finish.
Tapered end mills are center-cutting tools that manufacture angled slots and can be used for plunging. They are commonly seen in die-casting and molds.
Ball end mills are used to mill 3D forms or circular grooves and have rounded points.
These make it simple to cut precise keyways and T-slots for working tables and other applications.
The helix on straight flutesend mills is 0 degrees. They are ideal for materials like wood, polymers, and composites, where the lifting effect of a spiral flute could generate undesirable consequences. The straight flute delivers higher surface finishes than helical general purpose end mills for those materials.
This is the less expensive of the two, with good wear resistance and the ability to mill a wide range of materials, including wood, metals, and plastics.
Coated Carbide end mills are more expensive than HSS end mills, but they are more rigid and can be run two to three times faster. They are also quite heat resistant, so they are good for milling tougher materials.