Thursday, July 16, 2020

Selection of Tools and Toolholders for a Job - Process Planning


Gideon Halevi Book Chapter 11




1 Parameters to Consider

Insert shape, insert grade, toolholder type, method of holding the insert in the holder.

ISO standards

2 Selecting Insert Shape and Toolholder Type

The cutting edge angle must have an inclination of a minimum of 3 degree towards the machined face.

2.1 Selection of insert shape



2.2 Selecting the insert grade
P10 to P40 and K05 to K40 are illustrated in a figure.

3. Standards for Indexable Inserts

3.1 The first digit
First digit represent insert shape. Available shapes: Round, square, 80 degree/100 degree diamond, Triangle, 55 degree diamond, 35 degree diamond

3.2 The second digit
This digit represents clearance angle

3.3 The third digit
Tolerances

G represents ground insert. It is used for tolerances in the range 0.07 to 0.15 mm.

M represents unground insert.



3.4 The fourth digit
Type of insert

3.5 The fifth digit
Cutting edge length

Cutting edge length is related to the depth of cut.
Cutting edge length of the insert has to be at least double the maximum cutting edge engagement.

3.6 The sixth digit
Insert thickness (T)

It is calculated based on the formula

T = 3*L^3*f^0.6
L = cutting edge length engagement (mm)
f = feed rate (mm/revolution)

To specify commercially available thickness add zero before the result and specify whole number. For example 4.76 is 04, 6.35 will be 06.



3.7 The seventh digit
Tool nose radius

In the book  Table 5 in the chapter gives recommended nose radius as a function of depth of cut.

For a depth of cut less than 0.5mm, the recommended nose radius is 0.2 to 0.4 mm.
For 3 to 10mm d.o.c. 0.8 to 1 mm nose radius is recommended
For 20 to 30 mm d.o.c. 2 to 3 mm nose radius is recommended.


4. Standards for Toolholders

4.1 The first digit
Clamping system

A line contact is being used on the pocket wall for locating inserts in the pocket of the toolholder.

An unthreaded cam pin is used as locking member. Various tool manufacturers have patents on this method.

Top clamping method is there. There is hole clamping also.

4.2 The second digit
insert shape

4.3 The third digit
Toolholder type in relation to entering angles

The entering angle is referred to as cutting edge angle. Smaller cutting angles are preferred.
1. The cut is spread over a broader section of the cutting edge.
2. It has greater heat dissipating capacity
3. It protects the tool nose radius area.

Turning
http://www.mitsubishicarbide.com/en/technical_information/tec_turning_tools/tec_hsk-t/tec_hsk-t_technical/tec_turning_cutting_edge

Milling
http://www.mitsubishicarbide.com/en/technical_information/tec_rotating_tools/face_mills/tec_rotating_function_cutting_edge/tec_milling_function_cutting_edge_angle

Toolholder with shank offset can work nearer to the chuck jaws without turret carriage interference.


4.4 The fourth digit
Rake angle attitudes

4.5 The fifth digit
Toolholder version - Right, Left, Neutral

4.6 The sixth seventh eighth and ninth digits
Shank height, shank width

4.7 The tenth digit
Tool length

5 Review Questions

6 Conclusion


11. How to Select Tools for a Job 

1 Parameters to Consider

2 Selecting Insert Shape and Toolholder Type
2.1 Selection of insert shape
2.2 Selecting the insert grade

3. Standards for Indexable Inserts
3.1 The first digit
3.2 The second digit
3.3 The third digit
3.4 The fourth digit
3.5 The fifth digit
3.6 The sixth digit
3.7 The seventh digit

4. Standards for Toolholders
4.1 The first digit
4.2 The second digit
4.3 The third digit
4.4 The fourth digit
4.5 The fifth digit
4.6 The sixth seventh eighth and ninth digits
4.7 The tenth digit

5 Review Questions

6 Conclusion

Updated on 17 July 2020
11 May 2020

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