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The Beginners Guide of CNC End Mill

The Beginners Guide of CNC End Mill


If you are new to CNC processing, you may think that…
There are so many end mills in the catalog, what’s the difference? And which end mill should I use on my CNC machine?


First, we need to know, what is CNC End Mill for? 
Simply put, End Mill is one kind of milling cutter to do the process of removing metal by CNC Milling machines.
There are various diameters, flutes, lengths, and shapes to choose from. Basically, users choose them according to the material of the workpiece and the surface finish required for the workpiece.

So, let's start by introducing the appearance of the End Mill, including the shapes, flutes, geometry, and coating.

1. End Mill Shapes

A. Square End Mill:

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

 Square End MillRelated Products: SPEED TIGER Square End Mill

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 mill. 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. 

Ball NoseRelated Products: SPEED TIGER Ball Nose End Mill

C. Corner Radius End Mill:

Imagining 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.

 Corner Radius End MillRelated Products: SPEED TIGER Corner Radius End Mill

D. Taper End Mills:

Also known as pencil end mills and conical end mills, these names are used for describing the shape of its flute. They can produce grooves, holes, or side-milling with a slope angle. 

Taper End MillRelated Products: SPEED TIGER Taper End Mill

E. Long Neck End Mill:

The design can avoid the interference between the tool and workpiece by reducing the shank diameter behind the flute, which is ideal for deep slotting (deep pocketing). 


Long Neck End Mill 

F. CNC Router Bits:

CNC router bits are the cutting tools that work on a CNC router. They usually can be made to cut non-ferrous metals (soft materials), such as aluminum, brass, copper, MDF, plastic, PVC, wood, and more.

CNC Router Bits

Related Products: SPEED TIGER CNC Router Bits
 

2. End Mill Flutes

Which part is the 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, fewer flutes mean better chip evacuation, but at the expense of surface finish. More flutes give you a nicer surface finish, but worse chip removal.
 

Table of end mills flutes number

- The different performances of different numbers of flutes.

Number of Flutes

 1 flute

2 flutes

3 flutes

4 flutes

6 flutes

Rigidity

Poor

Fair

Average

Good

Excellent

Chip evacuation

Excellent

Excellent

Good

Fair

Poor

Wear time

Poor

Fair

Average

Good

Excellent

Vertical accuracy

Poor

Fair

Average

Good

Excellent

Surface roughness

Poor

Fair

Average

Good

Excellent

Performance on the soft material workpiece

Excellent

Excellent

Good

Fair

Poor

Performance on the hard material workpiece

Poor

Fair

Average

Good

Excellent

Performance on grooving/ slotting

Poor

Fair

Average

Good

Excellent

Performance on side milling

Poor

Fair

Average

Good

Excellent


- The effect of helix angle: 

Helix Angle

Helix Angle 15°

Helix Angle 35°

Helix Angle 45°

Helix Angle 55°

Surface roughness

Fair

Good

Excellent

Excellent

Surface fluctuation

Excellent

Good

Fair

Fair

Chip removal

Excellent

Good

Fair

Fair

Cutting torque

Excellent

Good

Average

Fair

Axial tension

Fair

Average

Good

Excellent

OD wear

Excellent

Good

Average

Fair

 

3. Detail of the end mill

SIDE VIEW of the end mill*SIDE VIEW of the end mill.
TOP VIEW*TOP VIEW of the end mill & EDGE of the end mill.

Related Article: End Mill Size Standards Chart & Information

 

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 spacesuit 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". 

 
Related Products Info:


 
  Square Type Square End Mill: also known as a "flat end mill".  The flutes are with sharp corners that are squared off at a 90° angle. They are the most popular and general milling cutters.
Ball Nose Ball Nose End Mill: It 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 mill.
Corner Radius End Mill Corner Radius End Mill: There is a radius form at a sharp corner of the square end mill, that's a corner radius milling tool.
taper end mill Taper End Mill, pencil end mills, or 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.
chamfer milling cutter 45°, 60°, 90°, 120°chamfer angles; can do top chamfer and bottom chamfer.
aluminum End Mill Aluminum Application Experts: Aluminum alloy is one of the exotic materials because the chips can stick to the flutes and pack, and Speed Tiger designed a series of Aluminum End Mill to meet many kinds of processing demands.

 If you have any questions or needs, please feel free to contact us! 
OR Custom End Mill for your project !
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