Application And Selection Of Chip Breaking Groove For Indexable Turning Blade

Generally, turning is a single edge continuous cutting process.

If no chip breaking measures are taken, the chips will not break naturally.

In this way, not only the cutting quality and productivity are affected, but also safety accidents sometimes occur.

Therefore, chip breaking is very important for turning.

With the development of industry and the continuous use of difficult to machine materials and CNC machine tools, the problem of chip breaking has become more prominent.

In addition, poor chip control will threaten the safety of operators, affect the service life of tools and the performance of machine tools, deteriorate the quality of machined surfaces, increase auxiliary working hours, etc.

Therefore, chip control is an important problem to be solved in metal cutting, especially in CNC and other automatic machine tools.

At present, the most commonly used method to control the chip to break reliably is to use the tool chip breaking groove.

Its principle is based on the work hardening effect of the material and the strain of the chip after impact and extrusion deformation is greater than or equal to the fracture strain of the material.

Because the chip formation mechanism is different under different conditions, the chip will show different shapes.

How to cut the chip through the appropriate tool groove shape and minimize the impact of chip on the cutting process is a problem that needs to be considered in actual production.

Necessary conditions for chip handling:

1) The chip breaking shall be smooth without affecting the normal cutting.

2) The volume of chips is controlled to make it easier to handle, store and transport the chips.

3) The chip shall be discharged without winding the workpiece, turning tool or causing failure of auxiliary devices (automatic feeder, etc.).

The chip breaking of the indexable turning tool is mainly realized by the chip breaking groove of the indexable blade.

(1) National standard chip breaking groove

The national standard gb/t2076-2007 specifies 13 types of chip breaking grooves.

At present, another part of the groove shapes recommended in the original ministerial standards issued by the Ministry of metallurgy are used in domestic production.

See table 3-9 for the code, form and scope of application of the commonly used national standards and the original ministerial standards.

Table 3-9 code, form and scope of application of chip breaking groove in common national standards and original standards

Code (subordinate standard)formfeaturesScope of application
A(GB、YB) The front and back are the same width, and the opening is not connected to the groove. The chip breaking range of this groove shape is relatively narrow. There are 7 kinds of groove width (mm), including 2, 3, 4, 5, 6, 8 and 10, which can be selected according to the processed materials and cutting parametersIt is mainly used for turning excircles and end faces with little change in cutting parameters, and its left blade is also used for inner hole boring cutter
C (GB) (YB is F) Front and rear equal width, equal depth, open half through groove, and the cutting edge has a 6 ° positive edge inclinationLarge chip breaking range, small unit cutting force and good chip removal effect
D(GB) There are a row of semicircular spherical pits along the cutting edge.It is mainly used for indexable bit blades. The cuttings are in pagoda shape and the effect is good.
H(GB、YB) The characteristics of the groove shape are similar to those of type A, but the groove is fully opened along one side of the cutting edge.It is mainly applicable to turning tools with Kr=45 ° and 75 ° and can be used for large amount of cutting.
J(GB)(YB is L) The groove shape is similar to H type, but the groove width is different. It is an outward inclined type with wide front and narrow rear.Large chip breaking range, suitable for rough turning.
K(GB)(YB is J) The groove shape is a half through groove with a narrow front and a wide rear and an opening.The purpose of the utility model is to cut at the point of the blade when the back edge is small, and the groove is narrower; When the back feed is large, the groove is correspondingly wider, the cutting deformation is more complex, it is easy to break, and the chip breaking range is wide.When turning the end face where chip breaking is difficult, the chip breaking effect is better.
V (GB、YB) Closed through groove with equal front and rear width.It is the most commonly used groove with a large chip breaking range. When the back feed and feed rate are small, it can also break chips well.It can be used for fine turning, semi fine turning and boring of outer circle, end face and inner hole.The strength of the blade tip is higher than that of the blade with open groove, which is suitable for rough turning.
W(GB、YB) It is a closed through groove with three-stage chip breaking.The chip breaking range is large, and the chip can be broken even when the back feed and feed are very small.However, because the front angle of this groove is small, the cutting force is relatively large, and the chips are easy to splash.It is applicable to the machining of copying lathes and automatic lathes with large range of cutting parameters and good rigidity of machine tools and workpieces.
Y(GB)(YB is D) The groove shape is an inclined half through groove with wide front and narrow rear.The groove shape is wider, and the cutting is lighter and faster, and the chip removal is smooth. Most of them are tubular spiral chips or conical spiral chips It is mainly used for rough turning with good chip breaking effect.
M(YB) The two-stage chip breaking groove and chip breaking range are wider than the single-stage chip breaking groove.   It is mainly used for profiling turning with large change of back cutting.
3C(YB) The sharp angle of the blade is 82 °, and the C-groove is an open half through groove with the same width and depth. At present, the groove width (mm) produced is 2, 3, 4, 5, 6, etc.It is mainly used for fine turning, semi fine turning and rough turning with small impact load.
Z(YB) The groove shape is very similar to the A-type groove, but it is smaller than the front angle of the A-type groove, and the chip curling angle is larger. The two corners are connected by straight lines, and it is also deeper and wider than the A-type groove.It is mainly applicable to rough machining of materials with high toughness.

Note: GB is the code of national standard and YB is the code of ministry standard.

(2) Chip breaking groove shape of turning blade

Chip breaking groove shape

(1) See table 3-10 for the chip breaking groove shape of the perforated negative angle blade.

Table 3-10 chip breaking groove shape of perforated negative angle blade

purpose

Chip breaking groove

Accuracy

Recommended cutting parameters

Features / blade profile

finish machining

 

 

 

M

ap=0.05~1(mm)f=0.05~0.35(mm/r)

Class P mild steel finish machining recommended groove shape M-class double-sided chip breaking groove, excellent chip breaking performance when machining class P mild steel and medium carbon steel, and high-quality machining surface can be obtained.

 

M

ap=0.3~2(mm)f=0.05~0.35(mm/r)

It is recommended to use M-class double-sided chip breaking groove for finishing of class P materials.

The chip breaking within the finishing range is ideal and the machined surface quality is high.

 

M

ap=0.05~1(mm)f=0.05~0.3(mm/r)

Recommended groove shape for finish machining of class M materials

M-level double-sided chip breaking groove with sharp edge can effectively solve the machining difficulties such as stainless steel chip breaking, tool sticking and surface hardening, and obtain high-quality machined surface.

 

E

ap=0.1~1(mm)f=0.050.3(mm/r)

Recommended groove shape for finishing of class s materials

Class E double-sided chip breaking groove, with high transposition accuracy, work hardening prevention and strong wear resistance, can obtain high machining accuracy and surface quality.

 

M

ap=0.5~3.0(mm)f=0.05~0.5(mm/r)

Finishing groove shape of polishing blade

Grade m double-sided chip breaking groove, with finishing groove shape designed by polishing blade, meets high workpiece surface quality, and excellent chip breaking performance, which is applicable to small feed and small cutting depth.

Semi finishing

 

 

 

M

ap=1.5~5(mm)f=0.15~0.5(mm/r)

Recommended groove shape for semi finishing of class P materials

M-class double-sided chip breaking groove has small cutting force and wide chip breaking range.

It can also obtain good chip breaking effect for alloy steel with high viscosity.

Purpose

Chip breaking groove

Accuracy

Recommended cutting parameters

Features / blade profile

Semi finishing

PM

 

M

ap=1.55(mm)f=0.15~0.5(mm/r)

Recommended groove shape for semi finishing of class P materials

M-class double-sided chip breaking groove, with higher edge strength than DM, is suitable for semi precision machining with unstable working conditions, and can also be used for cast iron machining to obtain low cutting force.

 

 

NM

 

M

ap=0.1~1.5(mm)f=0.05~0.3(mm/r)

Recommended groove shape for semi finishing of class s materials

M-level double-sided chip breaking groove has high transposition accuracy, strong work hardening prevention and wear resistance, and can obtain higher machining efficiency than F.

EM

M

ap=0.5~1.5(mm)f=0.1~0.3(mm/r)

Recommended groove shape for semi finishing of class M materials

M-level double-sided chip breaking groove can effectively solve the processing difficulties such as stainless steel chip breaking and tool sticking, and can obtain higher processing efficiency than EF.

WGM

M

ap=1.0~5.0(mm)f=0.15~0.80(mm/r)

Semi finishing groove shape of polishing edge

M-level double-sided chip breaking groove, with semi precision machining groove shape designed by polishing blade, the perfect combination of good polishing effect and solid blade structure greatly meets the processing requirements of high efficiency and high surface quality.

Through groove

 

M

ap=1.5~5(mm)f=0.2~0.5(mm/r)

Semi finish to rough machining of P, m and K materials

M-class double-sided chip breaking groove, with good edge strength and versatility.

Light load rough machining

LR single side

 

M

ap=3~12(mm)f=0.3~0.8(mm/r)

Recommended groove shape for light load rough machining of class P and K materials

M-class double-sided chip breaking groove, the groove shape is preferred for light load rough machining, and the metal removal rate and cutting edge economy can be achieved at the same time.

LR single side

 

M

ap=3~15(mm)f=0.3~1.0(mm/r)

Recommended groove shape for light rough machining of class P materials

The M-level single-sided universal chip breaking groove has a wide chip breaking range, a sharp cutting edge and a blade inclination design.

The cutting is light and fast, the chip flow direction is well controlled, and the chip guide boss can reduce the contact area with the chip, which is conducive to the heat dissipation of the blade.

purpose

Chip breaking groove

accuracy

Recommended cutting parameters

Features / blade profile

Rough machining

ER single / double sided

M

Single side: ap=2.58 (mm) f=0.2~0.6 (mm/r) double side: ap=2.520 (mm) f=0.2~1.2 (mm/r)

Recommended groove shape for rough machining of class M materials

The M-level single and double-sided chip breaking groove has strong impact resistance.

The groove shape design has achieved the best balance between the safety and sharpness of the cutting edge, and solved the difficulties such as large cutting heat and tool sticking in the rough machining of stainless steel, thus achieving high efficiency.

Dr single side

M

ap=3~15 (mm)

f=0.3~0.8(mm/r)

Recommended groove shape for rough machining of class P materials

The M-level single-sided chip breaking groove has high cutting edge safety.

 Under the processing parameters of large cutting depth and large feed rate, high metal removal rate and low cutting force can be obtained.

Heavy load machining

HDR single side

M

ap=5~15(mm)f=0.3~1.0(mm/r)

Recommended groove shape for heavy load machining of class P materials

Grade m single-sided chip breaking groove, with strong cutting edge, high safety, and strong plastic deformation resistance under high metal removal rate.

HPR single side

M

ap=3~17(mm)f=0.5~1.2(mm/r)

Recommended lees for heavy load processing of class P materials

M-level single-sided chip breaking groove with solid cutting edge and multiple chip guide bosses ensure chip outflow and blade heat dissipation.

N-It is mainly used in unstable working conditions and relatively difficult machining occasions, especially for “peeling”machining.

Cast iron processing

No slot

M

ap=0.3~12(mm)f=0.05~0.6(mm/r)

For cast iron processing

M-class double-sided, high cutting edge strength, is the solution to overcome the adverse processing factors such as sand holes and slag inclusion in cast iron processing.

Superhard blade

No slot

G

ap=0.05-0.5(mm)f=0.05~0.3(mm/r)

For processing materials with high hardness and non-ferrous metals

Grade G, PCBN and PCD superhard materials are welded to cemented carbide matrix, which is a solution for processing materials such as high hardness and non-ferrous metals.

Ceramic blade

No slot

G

ap=0.1~3(mm)f=0.05~0.4(mm/r)

For processing hard steel, cast iron, steel and other materials

Class G double-sided ceramic blade can be used to process hardened steel, cast iron, steel and other materials under different treatment conditions.

(2) See table 3-11 for the chip breaking groove shape of the perforated positive angle blade.

Table 3-11 chip breaking groove shape of perforated positive angle blade

purpose

Chip breaking groove

accuracy

Recommended cutting parameters

Features / blade profile

Precision machining

USF

G

ap=0.02~1.5(mm)f=0.01~0.08(mm/r)

Precision turning groove

Class g precision, large front angle design, sharp cutting edge, faster cutting whistle, is the preferred groove shape for precision turning of small shaft parts.

R/L

G

ap=0.052.5(mm)f=0.03~0.25(mm/r)

Recommended groove shape for precision boring blades

Class g precision, sharp edge and small arc of the tool tip effectively prevent vibration during machining.

It is suitable for precision boring and precision machining of excircles.

SF

G

ap=0.05~1(mm)

F=0.05~0.3(mm/r)

Precision machining groove shape meeting high chip breaking requirements

Class g precision, ideal chip breaking effect for finishing groove shape.

finish machining

HF

M

ap=0.1~2(mm)

f=0.05~0.3(mm/r)

Finish machining groove with strong versatility

Class M precision, suitable for internal and external finishing of steel, cast iron and other materials.

EF

M

ap=0.1~2(mm)

f=0.05~0.3(mm/r)

Recommended groove shape for finish machining of class M materials

Class m precision, sharp edge, suitable for finishing of stainless steel, mild steel and other viscous materials.

NF

EG

ap=0.05~1(mm)f=0.05~0.2(mm/r)

Recommended groove shape for finishing of class s materials

E. Class G precision, sharp edge, suitable for finishing inner hole and outer circle of superalloy materials.

Semi finishing

HM

M

ap=1~4(mm)

f=0.2~0.5(mm/r)

Semi finishing groove with strong versatility

Class M precision, suitable for semi finishing of inner hole and outer circle of steel, metal and other materials.

EM

M

ap=14(mm)

f=0.2~0.5(mm/r)

Recommended groove shape for semi finishing of class M materials

With M-level precision, the cutting edge strength is better than EF, and higher machining efficiency can be obtained than EF.

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