what is an end mill? 

By choosing the right end mill before turning on your CNC machine can be a pretty complex job. Many variables come into play, such as length of cut, geometry, profile type, material, while several trade-offs have to be considered: performance, cost, surface finish, tool life,...

What is an end mill actually, is it like a drill bit? It is a usual question that comes up since terminologies are often mixed up, but the answer is no. An end mill is a type of milling cutter, a cutting tool used in industrial milling applications. It is distinguished from the drill bit in its application, geometry, and manufacture. While a drill bit can only cut in the axial direction, most milling bits can cut in the radial direction. Not all mills can cut axially; those designed to cut axially are known as end mills. End mills are used in milling applications such as profile milling, tracer milling, face milling, and plunging. A drill bit is designed to plunge directly into the material and create holes only, while an end mill can cut laterally into the material and create slots or profiles. Besides, most end mills are designed to be centre-cutting, meaning they can plunge into the material as well and making them far more versatile than drill bits.

This article aims at explaining the basics of end mill science while answering the simple question you might have: which end mill should I use on my CNC machine?

Three major factors will influence your choice :

1. What kind of shapes do you want to for the mill ( 2 Flute Ball End Mill, 3Flute Square End Mill, 6 Flute Corner Radius End Mill,...)?

2. What kind of material do you want to for the mill?( Solid Carbide ,Diamond Coating,,....)

3. What are your goals in terms of performance and surface finish, while keeping an acceptable cost for you and staying within the capabilities of your CNC machine?

Answering these questions will help you determine the desired tool geometry, based on your project type, the material being cut and on the desired surface finish. So let’s dive into the theory and answer those questions later with some real examples.