Click the links below to learn more about the parts and the properties of the face mill!
Part names:
Rake angle:
Cutter
Attachment
Front
direction
Front
view
Back metal. A part that supports the cutting edge when it engages the workpiece and is exerted to high forces.
Shim/anvil. A shim/anvil is placed behind the insert to prevent the cutter body from being damaged.
Key way. A key way prevents the cutter from rotating.
Centering location bore. A locating bore to improve the location accuracy.
Bolt hole. A bolt hole to fix a cutter to an arbor.
(Cutting edge) Effective diameter. Outer diameter of cutting edge (wiper).
Chip pocket.A space designed to effectively discharge the chips generated when machining.
Insert.
Milling cutter
inserts
Portion machined
Tool rotation
Work piece
movement direction
Portion macined
Milling cutter
inserts
Tool rotation
Work piece
movement direction
x
Up and down cut milling
Up cut milling is a method of machining in which the direction of the cutter rotation and the feed direction of the workpiece are opposite. Down cut milling however is opposite to that of up cut milling. The direction of the cutter rotation and the feed direction of the workpiece are the same. When carrying out centre cutting, both up cut and down cut are simultaneously conducted. As one side of the centre line will be up cut whilst the opposite side will be down cut milling.
Which method to be used will depend on the machine and the face mill cutter that has been selected. Generally down cut machining offers longer tool life than up cut milling.
Wedge type
Insert
Insert locating method
Screw-on type
Wedge
Insert
Insert
Part names of insert
Main cutting edge angle of 45°
Main cutting edge angle of 90°
Maximum depth of cut
Main cutting edge
Effective diameter
Wiper
*1 Actual square inserts do not have excessive angles as shown.
*1
Wiper
Maximum depth of cut
Effective diameter
Number of teeth
By increasing the number of teeth in a face milling cutter it is possible to improve the machining efficiency. However it does lead to an increase in the cutting resistance or power required to carry out the machining.
Number of teeth
Coarse pitch
Fine pitch
Extra fine pitch
Figure
Applica-tion example
- Whe large chips are developed
- Poor rigidity
- General steel and
- stainless steel
- Used between coarse pitch and extra fine fitch
- Rigid setup
- When developing small chips
- Whe increasing table feed
- Cast iron
Wiper insert
It is difficult to ensure that all of the inserts fitted into a milling cutter are accurately set to the same cutting edge height. Therefore, as shown in animation 1 to the right, steps in the machined surface may occur.
Rake angle
A rake angle is an important factor to determine the sharpness of the cutting edge and the direction of chip flow. The picture shows various angles of a face mill cutter.
Cutting edge angles
Corner angle
(Main cutting edge)
Cutting edge angle
Axial rake angle
Radial rake angle
Positive and neagative rake angles
Wether rake angles (a radial rake angle, an axial rake angle, a true rake angle and a cutting edge inclination angle) are positive ( ) or negative (-) is determined by the inclination of the cutting edge. This can be seen in the images to the right.
- Click on the -, 0 and signes to view the different angles.
Negative rake angle
Neutral rake angle
Positive rake angle
Basic cutting edge configurations
Click on each picture to see an enlargement!
Double positive (DP)
Double negative (DN)
Negative positive (NP)
Single sided insert
Double sided insert
Single sided insert
Axial rake angle
Radial rake angle
x
Differential pitch
The term differential pitch is used to describe a process in which the cutting edges of a face mill are purposely designed at irregular pitches. An example of which can be seen in the picture.
For example, a face mill with six teeth, pitch angles in regular division are 60° each. Meanwhile, for differential pitch face mill cutters the pitch angles are 65°, 56°, 59°, 65°, 56° and 59°. The reason for the cutting edges to be designed with this differential pitch is to dampen out the vibrations encountered whilst machining.
Insert geometry
Typical insert geometries used for face milling cutters include pentagon, trigon, rectangle and round, in addition to the most commonly used triangular and square. Polygonal inserts have a larger number of usable corners. However, if the inserts inscribed circle is the same then the cutting edge length reduces.
Main cutting edge
Minor cutting edge
Main cutting edge
Main cutting
edge
Minor cutting edge
Minor cutting edge
Main cutting edge
Minor cutting edge
x