The Beginners Guide of CNC End Mill

1.End Mill Shapes

A. Square End Mill: Also known as a "flat end mill", which is the most common ones and can be used for many milling applications, including side milling, slotting, profiling and plunge cutting.

B. Ball Nose End Mill: The end flutes of Ball Nose End Mill is with no flat bottom. It's is ground with a full radius equal to half of the tool diameter. For example, you may say 5R to a 10mm ball nose end mills. Ball nose mills are used for contour milling, shallow pocketing and contouring applications, etc. They are especially good for 3D contouring because they leave a nice rounded edge. 

C. Corner Radius End Mill: Image there is a radius form at a sharp corner of square end mill, that's a corner radius milling tool. These are commonly used to mill mold & die as you don’t need to use nearly as many tool changes to get flat bottom pockets and rounded contours.
D. Taper End Mills: Also known as pencil end mills and conical end mills, these names are used to describe the shape of its flute. They can produce grooves, holes, or side-milling with a slope angle. 
taper end mill
E. Long Neck End Mill: The design is reduced shank diameter behind the flute length is used to avoid the workpiece, which is ideal for deep slotting (deep pocketing). 
End Mill FlutesWhich part is flute?

long neck end mill

2.End Mill Flutes

Which part is flute? 

The answer is the spiral channels on an end mill. And the design of the flute also will determine which materials you can cut.
The most common options are 2, 3, or 4 flutes. Generally, less flutes mean better chip evacuation, but at the expense of surface finish. More flutes give you a nicer surface finish, but worse chip removal.
Here is a table of the difference of different numbers of flutes to help you understand quickly.


3.Detail of the end mill
刀子介紹刀子介紹 p2
4. End Mill Coatings 

What does coating do?
To put it simply, the purpose of the coating is to extend tool life and improve performance.
Coating is like the clothes of an end mill. On different occasions, it needs to be worn the right clothes. For example, people need to wear a space suit when they are in outer space, and a swimsuit when they swim. Therefore, depending on your processing conditions, it will affect what coating you need to choose.

Basically, there are 2 kinds of thin film deposition, Physical Vapor Deposition (PVD), and Chemical Vapor Deposition (CVD). You may read more detailed coating information will in "End Mills need Coatings".