To begin with, let's take into account the fact that work on CNC machines is performed with general-purpose cutting tools (i.e., such a tool is used on machines with manual control). But everything is not so simple, because if the tool is used on CNC machines, then it must meet the following requirements: have a high quality sharpening, be interchangeable, must meet increased requirements for rigidity and wear resistance.

One type of cutting tool is a cutter. So, with a turning tool, you can perform many operations, including on CNC machines. And, of course, turning tools differ in purpose.

Therefore, the following subsystems were allocated:

Turning tools, performing such operations as turning, threading, boring, grooving, cutting on machines of medium and light series;

Turning cutters that perform special work (for example, a shaped cutter or a cutter for plasma machining);

Turning tools, which are installed on heavy, carousel and large machines;

Lathe cutters installed on TPM and multi-purpose machines.

Subsystem of cutters for CNC machines.

Let's take a closer look at the cutting tool subsystem for CNC machine tools. So, for example, a cutter with a modernized wedge fastening of the SMP - a wedge-clutch, is used to carry out preliminary and final operations on universal machines. The bottom line is to press the SMP with a wedge to the pin and to the base plate. With this fixing, we can observe an open auxiliary cutting edge.

Now, let's look at the cutter subsystems that make up the grooving cutters and turning cut-off cutters.

So, based on the structural features, the incisor can be:

1. Cut-off tool holder, in which replaceable non-regrowth carbide cutting inserts have a mechanical fastening.

This cutter has in its structure: a spring-loaded grip, a non-overlapping single-edge cutting insert, a holder.

In order to install the cutting insert into the V-shaped groove of the holder socket, a V-shaped protrusion is required directly on the supporting surface of this very insert.

I would also like to note that if the cutting inserts are made of hard alloys with a wear-resistant coating, then the resistance increases by 2-3 times.

2. Cut-off, having brazed carbide plates.

New (and three-layer including) brands of solders are already used here for manufacturing. And the holder can be made of steel 35HGSA, or 30HGSA, which significantly reduces, or rather, virtually eliminates cracking during brazing. thus, cutter consumption is reduced by 3-4 times.

Highly good quality and the accuracy of sharpening leads to a decrease in the cost of primary sharpening (by about 0.3 - 0.4 rubles).

3. Grooving tool holder, in which replaceable re-sharpened carbide cutting inserts have a mechanical fastening.

From the name it is clear that such a cutter must be used to cut a groove (with exact dimensions). The cutting element is nothing more than a carbide plate made in accordance with GOST 2209-83. The structure of this cutter includes: a holder, a cutting plate (the shape of which is prismatic), a thrust element (in the form of a biscuit), an adjusting screw and a clamp.

To prevent transverse displacements of the supporting surface of the cutting plate, it (the plate) is made at an angle to the lateral one, and fixation occurs with a stick. The adjusting screw ensures the overhang of the cutting insert after regrinding, and in the future - fixing this very insert, thereby preventing longitudinal displacement.

The basis of this design was the production of flute cutters, which allow machining of internal threaded, angular, straight grooves and external angular and straight grooves.

Well, it is worth noting that rational operation involves at least 20 regrindings.

4. Cut-off plate, having replaceable carbide cutting inserts.

(But, such a cutter is primarily applicable for universal machine tools with manual control)

Such a cutter has in its structure: a block (which is fixed in a tool holder), a two-edged, non-sharpened cutting insert, which is fixed by an elastic petal of the holder, a plate holder.

The cutter becomes more versatile because the plate holder allows you to adjust the parameters of its protrusion from the block to a given size.

5. Grooving, in which replaceable non-regrowth carbide cutting inserts have a mechanical fastening.

This type of cutter has in its structure: a holder, a clamping screw with a washer, a double-edged cutting insert. The cutting plate is secured with a screw. With regard to the presence of two cutting edges, this saves carbide.

Further, it is worth noting the general-purpose cutter subsystem, consisting of prefabricated cutters, which allow for rough, semi-finishing and finishing turning of workpieces made of cast iron and steel.

Thus, the workpieces can be turned, trimmed, machined, slotted, boring.

The subsystem includes a small number of groups:

TTO

The cutter of this group is installed on heavy lathes (workpiece diameter 1250 - 4000 millimeters) and on rotary lathes (workpiece diameter 3200 - 12000 millimeters), which have conventional tool holders.

CCI

The cutter of this group is installed on heavy lathes with CNC plate tool holders.

WHO

The cutter of this group is installed on large lathes (workpiece diameter 800 - 1000 millimeters) with standard tool holders, and rotary lathes (workpiece diameter 1600 - 2800 millimeters).

It is necessary to improve the quality of the cutting tool in all possible ways, including, using the experience of inventors, to develop new methods of fixing and changing inserts, to use progressive technologies to increase labor productivity.

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Cutters for CNC machines

Introduction

Turning cutters are designed to perform the whole variety of different operations on CNC machines, on PMG and FPS, as well as on manual turning machines.

Differences in the purpose of turning tools.

By designation, the turning tool system is subdivided into the following subsystems: cutter lathe sharpening

For external turning, boring, threading, cutting groove cutting on light and medium series machines;

For work on heavy, large lathes and boring machines;

For work on PMM, multi-purpose machines with built-in robotic systems for automatic tool change;

For special work (cutters for plasma machining, shaped).

Each of the subsystems has its own specific features due to many factors, primarily the design of the equipment, its technological purpose, etc. The incisor system is based on general methodological principles and provides for:

Development (selection) and unification of reliable methods for fixing replaceable inserts in the holder (including solid and composite cutters, with brazed plates, prefabricated);

Ensuring satisfactory crushing and removal of chips from the cutting zone;

Sufficiently high positioning accuracy of the tops of the removable plates (due to the creation of precise bases of the socket);

Quick change and ease of removal and replacement of replaceable plates, cutting element or cassette (block);

Unification and maximum allowable reduction (reduction to the optimal value of technical and economic indicators of industrial production and use) of the number of methods for fixing plates in the holder;

The ability to use the entire range and sizes of replaceable plates of domestic and foreign production;

Compliance of the precision parameters of the cutters with international standards;

Obligation to use special parts of fasteners (screws, pins, etc.) of increased accuracy and reliability; development of new shapes and sizes of cutting plates, shapes of their front surfaces, providing satisfactory crushing and removal of chips;

Leveraging the experience of innovators and inventors;

The use of advanced resource-saving technologies for the manufacture of fasteners, keys; manufacturability and cost-effectiveness of manufacturing (saving materials and labor resources);

The possibility of using composite (found, solid, glued and other similar joints) carbide inserts with tool blocks (holders) in cases of their undoubted technical and economic efficiency or the impossibility of a design solution for a cutter in a prefabricated version (primarily for small sections of holders, some boring and cutting operations, etc.).

Subsystems of cutter designs are created on the basis of the generally accepted world practice system of holder shapes and plan angles to ensure all turning operations. For example, international (ISO 5910, 5909, etc.) and domestic standards are envisaged for the subsystem of external turning and boring of the shape of holders, which ensure the implementation of the whole variety of turning transitions.

1. Basic cutter schemes

At present, despite the huge variety of designs and schemes of attachment points for replaceable multi-faceted inserts in holders, leading foreign manufacturers of cutters use a very limited number of clamping methods in batch production. Their number is also limited in domestic cutter subsystems. For example, in the subsystems for external turning and boring on light and medium series machines, four basic schemes for the design of SMP fasteners are adopted (designation of fasteners according to GOST 26476-85):

Without hole - with a claw (type C);

With a cylindrical hole - lever mechanism (type P);

Pin and clamp (type M);

With toroidal hole - screw mechanism (type S).

Plates without holes are fixed according to method C. The design is adopted as a basis, which is widely used in automobile factories. With this method of clamping, the cutting inserts are based in the closed socket of the holder along two base surfaces and are pressed from above to the supporting surface with a tack. A quick release of the plates is provided by a differential screw. The carbide support plate is secured with a screw on the tool holder or with a split spring sleeve.

Cutters with an insertion hole according to method C are available in different versions: for cutting inserts with and without a clearance angle; with base plates; without base plates.

It should be noted that the back angle PFMs have 2 times more cutting edges than the back side PFMs. Chip-breaking grooves for crushing and removing drain chips are made on the front surface of the MPS with a clearance angle. When using an SMP without a clearance angle, overhead chip breakers are used.

Cutters with a base plate are widely used in turning and boring; cutters without a base plate - when boring small holes and turning on light series machines (section h [b tool holder 12 x 12 ... 16 x 16 mm). The operation of the cutters has shown that when working on universal and special machines in large-scale and mass production, cutters with carbide chip breakers have proven themselves well.

In such cutters, you can use an SMP made of hard alloy, ceramics, etc.

Inserts with positive angles provide a reduction in cutting forces, so they are recommended for use when machining non-rigid parts. These cutters can also be used with overhead chipbreakers. For external turning and boring in cutters with fastening according to method C, square, triangular, rhombic inserts are used, as well as parallelogram inserts of the KNUX type with fastening with a special figured grip. The SMP with a central cylindrical hole is fixed with a lever mechanism according to the P method and a modernized wedge fastening (wedge-intercept) according to the M method. Securing by a lever mechanism is the most rational for cutters with a section of holders from 20 x 20 to 40 x 40 mm. This design is effectively used on CNC machines. A domestic original design of the lever mechanism has been developed, which corresponds to the best world standards, and by purpose it is completely unified with the designs of cutters produced at some large machine-building plants of the domestic industry, and with tools manufactured abroad.

The SMP is based in a closed socket of the holder, and a lever, driven by a screw, pulls it to the two side walls of the socket and reliably presses it against the support. The base plate is secured with a split sleeve.

The design of the attachment unit provides the ability to quickly and accurately turn or change the SMP and secure it securely. It allows the whole range of new progressive domestic and foreign inserts, as well as inserts with a complex shape of the front surface, which provides good chip crushing in a wide range of feeds and cutting depths.

For contouring on machines with CNC, PMG and FPS, which makes it possible to grind several surfaces of a part in one working stroke, cutters with srombotic inserts are used ((= 80 (and 55 (). Industrial batches of cutters with an L-shaped lever for external turning and boring) are widely mastered in serial production by the tool factories of the Ministry of Stankprom, they are produced according to TU2-035-892 and GOST 26613-85.

2. Subsystem of cutters for CNC machines

To perform preliminary and final operations with one cutter, first of all, a range of cutters with a modernized wedge fastening of the SMP wedge-clutch (method M) has been developed on a universal machine with manual control. The wedge presses the SMP not only to the pin on which it is installed with the central hole, but also to the support plate. With this fastening of the SMP, the auxiliary cutting edge remains open. A subsystem of turning cut-off and grooving cutters for CNC and PMG machines has also been developed, which includes the following cutters. 1. High reliability cut-off tools with brazed carbide inserts. They are distinguished from cutting tools produced in accordance with GOST 18884-73:

Increased manufacturing accuracy and relative positioning of the holder surfaces, which ensures their use on CNC machines;

The use of new, including three-layer, grades of solders and replacement of the holder material with steel 35HGSA or 30HGSA practically excludes cracking during brazing, which will reduce the consumption of cutters by about 3-4 times;

The increased quality and accuracy of sharpening of the cutter reduce consumer costs for primary sharpening by 0.3-0.4 r;

Improved appearance.

The main dimensional parameters of the cutters fully comply with the ISO243-1975 (E) standard.

2. Cut-off toolholders with mechanical fastening of replaceable non-regrowth carbide cutting inserts.

The cutter consists of a holder, a single-edged, non-overlapping cutting insert, a spring-loaded grip. A V-shaped protrusion is made on the supporting surface of the cutting insert, with which it is installed in the V-shaped groove of the holder socket. When fastening, it is guaranteed that the cutting insert is pressed from the side of the thrust surface of the socket. The geometrical parameters of the cutting part provide good chip evacuation from the cutting zone, which is especially important when machining workpieces made of viscous materials.

The use of cutting inserts made of hard alloys with a wear-resistant coating provides a 2-4 times increase in tool life.

3. Cut-off plate cutters with mechanical fastening of replaceable non-regrowth carbide cutting inserts are intended for cutting off operations primarily on universal machines with manual control. The cutter consists of a block fixed in the machine tool holder, a plate holder and a two-edge, non-overlapping cutting insert, which is fixed by an elastic petal of the holder. The supporting surfaces of the cutting insert are made in the form of V-shaped grooves, with which it interacts with the V-shaped protrusions of the socket and the elastic petal of the holder.

Reducing the width of one of the two cutting edges by 0.3-0.4 mm ensures the operability of each cutting edge within the standard average service life, but for this, the worn, worn-out edge must be reground by 0.3-0.4 mm. This technical solution provides savings in carbide.

The plate holder allows you to adjust the value of its overhang from the block to the required size, which makes the cutter more versatile. The shape of the front surface of the cutting inserts ensures satisfactory chip formation and good chip evacuation when machining workpieces from various steels in a wide range of feeds.

4. Grooving tool holders with mechanical fastening of replaceable re-sharpened carbide cutting inserts are designed to work on universal and CNC machines. They are used primarily for precise grooving. Carbide plates produced in accordance with GOST 2209-83 are used as a cutting element.

The outer shape of the cutting part and the required size are provided by sharpening. The maximum width of the cutting edge is 4.8 mm. The cutter consists of a holder, a prism-shaped cutting insert, a grip and a thrust piece in the form of a cracker and an adjusting screw. The supporting surface of the cutting insert is made at an angle to the lateral one, which ensures its fixation against lateral displacements when fastening with a grip. Departure of the cutting insert after regrinding and fixing it from longitudinal displacement is provided by an adjusting screw.

On the basis of this design, grooving cutters for processing external straight and angular grooves have been mastered and mass-produced; for machining internal straight, angle and thread grooves. With rational operation, the permissible number of regrindings is at least 20.

5. Grooving cutters with a mechanical fastening of replaceable non-regrowth carbide cutting inserts consist of a holder, a two-edged cutting insert and a clamping screw with a washer. The supporting surfaces of the cutting insert are made in the form of V-shaped grooves, with which it interacts with the V-shaped projections of the socket. The cutting insert is secured with a screw interacting with the upper part of the slot formed by the slot in the holder.

Accuracy of locating and fixation of the cutting insert against longitudinal displacement is ensured by the presence of a thrust base surface in the socket.

The ratio of the groove depth to its width ranges from 1.0 to 2.0, depending on the width of the cutting part.

Having two cutting edges on the insert saves carbide. The shape of the leading surface of the cutting inserts provides satisfactory chip formation and good chip evacuation over a wide range of feeds.

The presented range of cutters provides the ability to perform all types of cutting and grooving operations.

To cut threads on lathes, cutters with brazed carbide plates according to GOST 18885-73 are used, with mechanical fastening of carbide plates.

The design of the cutter with mechanical fastening of the regrindable plates is similar to the design of the grooving cutter for cutting straight grooves, the only difference is in the sharpening of the cutting insert with a profile angle at the vertex equal to 59 (30). With the accepted width of the insert used, the pitch of the thread to be cut is provided from 0.8 to 3.5 mm. Precise grinding (sharpening) of the profile of the cutting part provides a cut thread with an average degree of accuracy.

In cutters with a mechanical fastening of a rhombic, non-regrowth cutting insert, the required geometry of the cutting part of the insert is ensured by pressing and sintering. For reliable fastening of the cutting insert in the blind socket of the holder, there is a V-shaped groove on its front surface, intended for connection with a stuck. The pitch of the threads to be cut is in the range from 2.5 to 6.0 mm.

Threads of a special profile on pipes, couplings, nipples and locks of oil and geological exploration equipment, depending on the profile of the thread, are cut with the following cutters:

Preliminary - cutters equipped with triangular shaped inserts in accordance with GOST 19043-80 and GOST 19044-80;

The final - with cutters equipped with square or triangular plates with a cutting part, the profile of which is obtained by grinding.

Plates without a hole are fixed using method C, and plates with a hole

Pulling grip. The profile of the cutting part can be multi-fluted (up to five) on one cutting edge; the range of steps of the threads to be cut is in the range from 2.54 to 6.35 mm. The number of working strokes, depending on the step, from 2 to 12.

Let us consider a subsystem of wide-purpose cutters for machining on heavy and large lathes, turning-boring and rolling lathes, including CNC machines. Such cutters can be used for other heavy metal cutting equipment. The subsystem includes prefabricated cutters for roughing, semi-finishing and finishing turning of workpieces made of steel, cast iron and other materials of any hardness with a depth of cut for roughing up to 50 mm and feed up to 10 mm / rev. Cutters perform turning, trimming, boring of large diameters, cutting and parting off, processing of transition surfaces.

The subsystem consists of several groups:

ТТО - for heavy lathes with the largest diameter of the workpiece being installed 1250-4000 mm and for rotary lathes with the largest diameter of the workpiece being installed 3200-12000 mm, having conventional tool holders;

TTP - for heavy lathes with plate tool holders of CNC machines;

KTO - for large lathes with the largest diameter of the workpiece being installed 800-1000 mm, with standard turning tool holders, and rotary lathes with the largest diameter of the workpiece being installed 1600-2800 mm.

In the TTO group, there are two types of cutter up to its supporting surface.

On the main body K1, a set of quick-change blocks B1 is fixed (right and left through, through thrust, undercut, etc.). These blocks are designed for machining with large depths of cut (t = 12 ... 40 mm), including roughing and interrupted cutting. Auxiliary body K2 is provided for fixing cutters of the KTO group (t = 10 ... 20 mm), as well as standard (t (8 mm).

In the TTP group, there are three types of L-shaped tool bodies of various widths for plate tool holders, which provide a minimum overhang of the cutter head and high rigidity of the support with a tool holder. On the K4 body, B1 blocks for large cutting depths are attached, on the K5 body - cutters of the KTO group for medium cutting depths and on the K6 body - B "blocks for small cutting depths.

Various articulations of bodies, blocks, cutters and plates make it possible to obtain only for a part of the subsystem more than 200 types of tools for various transitions with different main angles in plan and blade lengths l.

In the developed subsystem for especially severe cutting conditions, plates with a step P1 (TU 48-19-373-83) are used. The inserts are characterized by a slight increase in thickness with a corresponding decrease in width, which leads to a further increase in the strength of the tool.

The use of cutters with shoulder plates, with their rational fastening and basing, provides an increase in feed by 20-40% compared to the feed when machining with cutters with a brazed plate (which is 10-15% higher compared to the best assembled cutters of foreign companies).

For semi-finishing with shallower cutting depths, a thickened polyhedral P3 insert with a hole is used. The new design of the fastening unit ensures reliable clamping of this plate to the supporting and abutting surfaces.

3. Tool materials

Cutting tools are made in whole or in part from tool steels and hard alloys.

Tool steels are divided into carbon, alloy and high-speed. Carbon tool steels are used to make tools that operate at low cutting speeds. Knives, scissors, saws are made from carbon steel grades U9 and U10A, from U11, U11F, U12 - locksmith taps, files, etc. fractions of a percent, and the letter A - that high-quality carbon steel, as it contains sulfur and phosphorus no more than 0.03% each.

The main properties of these steels are high hardness (HRC 62-65) and low heat resistance. Heat resistance refers to the temperature at which the tool material retains its high hardness (HRC 60) with repeated heating. For steels U10A - U13A, the heat resistance is 220 (C, therefore, the recommended cutting speed with a tool from these steels should be no more than 8-10 m / min.

Alloyed tool steels are chromium (X), chromium-silicon (CS) and chromium-tungsten-manganese (CVG), etc.

The numbers in the steel grade indicate the composition (in percentage) of the constituent components. The first number to the left of the letter indicates the carbon content in tenths of a percent. The numbers to the right of the letter indicate the average percentage of the alloying element. If the content of the alloying element or carbon is close to 1%, the figure is not put.

Taps, dies, cutters are made of grade X steel; made of steel 9ХС, ХГС

Drills, reamers, taps and dies; from steel ХВ4, ХВ5 - drills, taps, reamers; from steel KhVG - long taps and reamers, dies, shaped cutters.

The heat resistance of alloyed tool steels reaches 250-260 (C and therefore the permissible cutting speeds for them are 1.2-1.5 times higher than for carbon steels.

High-speed (high-alloyed) steels are used for the manufacture of various tools, but more often drills, countersinks, taps.

High-speed steels are designated by letters and numbers, for example P9, P6M3, etc. The first P (rapid) means that the steel is high-speed. The numbers after it indicate the average percentage of tungsten. The rest of the letters and numbers mean the same as in the grades of alloy steels.

These groups of high speed steels differ in properties and fields of application. Steels of normal performance, having a hardness up to HRC65, heat resistance up to 620 (C and a flexural strength of 3000-4000 MPa, are intended for processing carbon and low-alloy steels with a tensile strength of up to 1000 MPa, gray cast iron and non-ferrous metals. Normal performance steels include tungsten grades P18, P12, P9, P9F5 and tungsten-molybdenum grades P6M3, P6M5, retaining hardness not lower than HRC 62 up to a temperature of 620.

High-speed steels of increased productivity, alloyed with cobalt or vanadium, with hardness up to YRC 73-70 and heat resistance 730- 650 other Improvement of the cutting properties of steel is achieved by increasing the carbon content in it from 0.8 to 1%, as well as additional alloying with zirconium, nitrogen, vanadium, silicon and other elements. , R9M4EV, R9K5, R9K10, R10K5F5, R18K5F2, retaining hardness HRC 64 up to a temperature of 630-640.

Hard alloys are divided into cermet and mineral ceramic, they are produced in the form of plates of various shapes. Tools equipped with carbide inserts allow higher cutting speeds than HSS tools.

Cermet hard alloys are divided into tungsten, titanium-tungsten, titanium-tantalum-tungsten.

Tungsten alloys of the VK group consist of tungsten and cobalt carbides. They use alloys of grades VK3, VK3M, VK4, VK6, VK60M, VK8, VK10M. The letter B stands for tungsten carbide, K stands for cobalt, the number stands for the percentage of cobalt (the rest is tungsten carbide). The letter M at the end of some grades means that the alloy is fine-grained. This alloy structure increases the wear resistance of the tool, but decreases the impact resistance. Tungsten alloys are used for processing cast iron, non-ferrous metals and their alloys and non-metallic materials (rubber, plastic, fiber, glass, etc.).

Titanium-tungsten alloys of the TK group consist of tungsten, titanium and cobalt carbides. This group includes alloys of grades T5K10, T5K12, T14K8, T15K6, T30K4. The letter T and the number indicate the percentage of titanium carbide, the letter K and the number behind it indicate the percentage of cobalt carbide, the rest in this alloy- Wolfram carbide. These alloys are used for processing all types of steels.

Titanium-tantalum-tungsten alloys of the TTK group consist of tungsten, titanium, tantalum and cobalt carbides. This group includes alloys of grades TT7K12 and TT10KV-B, containing, respectively, 7 and 10% titanium and tantalum carbides, 12 and 8% cobalt, the rest is tungsten carbide. These grades work in particularly harsh processing conditions when the use of other tool materials is not effective.

Alloys with a lower percentage of cobalt, grades VK3, VK4, have a lower toughness; used for processing with the removal of thin chips in finishing operations. Alloys with a higher content of cobalt grades VK8, T14K8, T5K10 have a higher viscosity, they are used for processing with the removal of thick chips in roughing operations.

Fine-grained hard alloys of the VK3M, VK6M, VK10M grades and coarse-grained alloys of the VK4 and T5K12 grades are used under pulsating loads and in the processing of difficult-to-machine stainless, heat-resistant and titanium alloys.

Carbide alloys have high heat resistance. Tungsten and titanium-tungsten hard alloys retain their hardness at a temperature in the processing zone of 800-950 (C, which allows you to work at high cutting speeds (up to 500m / min when processing steels and 2700m / min when processing aluminum).

Particularly fine-grained tungsten-cobalt alloys of the OM group are intended for processing parts made of stainless, heat-resistant and other difficult-to-machine steels and alloys: VK60OM - for finishing, and alloys VK10-OM and VK15-OM - for semi-finishing and roughing. Further development and improvement of alloys for processing difficult-to-machine materials caused the appearance of alloys of grades VK10-KhOM and VK15-KhOM, in which tantalum carbide was replaced by chromium carbide. Alloying alloys with chromium carbide increases their hardness and strength at elevated temperatures.

To increase the strength of the hard alloy plates, they are clad with protective films. Wear-resistant coatings made of titanium carbides applied to the surface of hard-alloy in the form of a thin layer 5-10 mm thick are widely used. In this case, a fine-grained titanium carbide layer is formed on the surface of hard-alloy plates, which has high hardness, wear resistance and chemical resistance at high temperatures... The durability of coated carbide inserts is on average 1.5-3 times higher than that of conventional inserts, the cutting speed can be increased by 25-80%. In severe cutting conditions, when chipping and chipping are observed with conventional inserts, the effectiveness of coated inserts is reduced.

The industry has mastered economical tungsten-free hard alloys based on titanium carbide and niobium, titanium carbonitrides on a nickel-molybdenum bond. Tungsten-free hard alloys of brands TM1, TM3, TN-20, TN-30, KNT-16 are used. They have a high scale resistance, exceeding the resistance of titanium carbide-based alloys (T15K6, T15K10) by more than 5-10 times. When machining at high cutting speeds, a thin oxide film forms on the surface of the alloy, which acts as a solid lubricant, which increases the wear resistance and reduces the roughness of the machined surface. At the same time, tungsten-free hard alloys have lower impact toughness and thermal conductivity, as well as resistance to impact loads than alloys of the TK group. This allows them to be used for finishing and semi-finishing machining of structural and low-alloy steels and non-ferrous metals.

Oxide (white) ceramics of the TsM-332, VO13 and VSh-75 grades are widespread among the mineral-ceramic materials, the main part of which is aluminum oxide with the addition of relatively rare elements: tungsten, titanium, tantalum and cobalt. It is distinguished by high heat resistance (up to 1200 (C) and wear resistance, which makes it possible to process metal at high cutting speeds (with fine turning of cast iron - up to 3700 m / min), which are 2 times higher than for hard alloys. cutting tools use cutting (black) ceramics of grades B3, VOK-60, VOK-63, VOK-71.

Cutting ceramics (cermet) is an oxide-carbide compound of aluminum oxides and 30-40% tungsten and molybdenum or molybdenum and chromium carbides and refractory bonds. The introduction of metals or metal carbides into the composition of mineral ceramics improves its physical and mechanical properties, and also reduces brittleness. This allows you to increase processing productivity by increasing the cutting speed. Semi-finishing and finishing machining of parts made of gray, malleable cast irons, hard-to-machine steels, some non-ferrous metals and alloys is performed at a cutting speed of 435-1000 m / min without cutting fluid. Cutting ceramics are highly heat resistant.

Oxide-nitride ceramics consists of silicon nitrides and refractory materials with the inclusion of aluminum oxide and other components (silinit-R and cortinite ONT-20).

Silinit-R is not inferior in strength to oxide-carbide mineral ceramics, but it has a higher hardness (HRA 94-96) and stability of properties at high temperatures.

Hardened and case-hardened steels (HRC 40-67), high-strength cast irons, hard alloys such as VK25 and VK15, fiberglass and other materials are processed with a tool, the cutting part of which is made of large polycrystals with a diameter of 3-6 mm and a length of 4-5 mm based on cubic nitride bora (elbor-R, cubonite-R, hexanite-R). In terms of hardness, Elbor-R is close to diamond (86000 MPa), and its heat resistance is 2 times higher than that of diamond. Elbor-R is chemically inert to iron-based materials. The compressive strength of polycrystals reaches 4000-5000 MPa, for bending 700 MPa, heat resistance - 1350-1450 (C. Abrasive materials include normal alumina grades 14A, 15A and 16A, white alumina grades 23A, 24A and 25A, mono-corundum grades 43A, 44A and 45A. Green silicon carbide grades 63C and 64C and black grades 53C and 54C, boron carbide, elbor, synthetic diamond, etc.

Powders are made from abrasive materials, which are intended for cutting in a free and in a bound state in the form of an abrasive tool (grinding wheels, bars, skins, belts, etc.) and pastes.

4. Sharpening of incisors

At machine-building enterprises, the tool is usually sharpened centrally. However, it is sometimes necessary to sharpen the tool by hand.

For manual sharpening of the tool, grinding and grinding machines are used, for example, a machine model 3B633, consisting of a grinding head and a bed. The grinding head has a built-in two-speed electric motor. At the outgoing ends of the rotor shaft, grinding wheels are attached, which are covered with casings with protective screens. The machine is equipped with a turntable or a tool for setting the cutter. The bed houses the electrical cabinet and the control panel.

Grinding machines, depending on the purpose and size of grinding wheels, can be divided into three groups: small machines with a circle with a diameter of 100-175 mm for sharpening small tools, medium machines with a wheel with a diameter of 200-350 mm for sharpening the main types of cutters and other tools, large machines with a wheel with a diameter of 400 mm and more for grinding parts and roughing and cleaning work.

The incisors, depending on their design and the nature of wear, are sharpened on the front, back, or on both surfaces. Standard carbide or HSS cutters are most commonly sharpened over all cutting surfaces. In some cases, with slight wear of the cutters along the front surface, they are sharpened only along the rear surface.

When sharpening on grinding and grinding machines, the cutter is placed on a turntable or hand-hand and manually pressed against the grinding wheel with the surface to be processed. For uniform wear of the wheel, the cutter must be moved along the table or a handyman relative to the working surface of the wheel.

When sharpening the cutter along the rear surfaces, the table or the handcuff is turned by a given rear angle and fixed in close proximity to the circle. The cutter is installed on a table or a handcuff so that the cutting edge is parallel to the working surface of the circle. The front surface of the cutter is most often sharpened with the lateral surface of the circle, while the cutter is installed on the side surface of the handcuff. The front surface can also be sharpened with the periphery of the circle, but this method is less convenient. HSS cutters are sharpened first along the front, then along the main and auxiliary rear surfaces. When sharpening carbide cutters, the same procedure is used, but the rear surfaces of the rod are pretreated at an angle 2-3 more than the sharpening angle on the carbide plate.

The quality of sharpening depends on the qualifications of the worker doing the sharpening and the characteristics of the grinding wheels. With an increase in the pressing force of the tool against the grinding wheel, labor productivity increases, but at the same time, burns and cracks may occur. Typically, the clamping force does not exceed 20-30 N. With an increase in the longitudinal feed, the likelihood of cracking decreases.

Usually, grinding wheels of different characteristics are installed on a grinding and grinding machine, which allows preliminary and final sharpening of the tool. When pre-sharpening a carbide tool, use wheels made of carbide, silicon (24A) with a grain size of 40, 25, 16 and a hardness of CM2 and C1 on a ceramic bond (K5); the final sharpening (with an allowance of 0.1-0.3 mm) is performed on diamond, CBN and fine-grained abrasive wheels with a bakelite bond.

For preliminary sharpening of high-speed tools, grinding wheels made of electrocorundum (23A, 24A) with a grain size of 40, 25, 16 and hardness CM1, CM2 on a ceramic bond (K5) are used. The final sharpening (with an allowance of 0.1-0.3 mm) is performed with circles of electrocorundum (23A, 24A) or mono-corundum (43A, 45A) with a grain size of 25, 16 and 12 and a hardness of M3, CM1, CM2 with a non-ceramic bond (K5). The roughness of the tool surface after preliminary sharpening is equal to 2.5-0.63 microns, after the final - 0.63-0.1 mm in Ra.

When sharpening a cutter on a fine-grained wheel, irregularities remain on the cutting edge, which directly affect the wear rate of the cutter. Therefore, after sharpening, the cutter is adjusted on a diamond wheel or on rotating cast-iron discs using abrasive pastes. The speed of rotation of the diamond wheel is up to 25 m / s, the speed of rotation of the disk is 1-1.5 m / s. The cutter is adjusted along the main back and front surfaces on a chamfer of 1.5-4 mm. The auxiliary posterior surface of the cutter is not machined.

To obtain high quality surfaces (Ra = 0.32 (0.08 μm), it is necessary that the runout of the finishing disc or wheel does not exceed 0.05 mm, while their rotation should be directed under the cutting edge. Lightly wipe with a felt brush dipped in kerosene. The layer of paste applied to the disc should be thin, since a thick layer does not accelerate the lapping process. only increases the consumption of the paste and accelerates the wear of the disc.

Checking the sharpening angles of the cutter can be done with templates and devices.

The drills are sharpened along the flank surface, giving it a curved shape to ensure equal clearance angles in any section of the cutting teeth. To do this, the drill is pressed against the grinding wheel and rotated at the same time. First, sharpen the surface near the cutting edge, and then the surface located at a large clearance angle. For carbide drills, the insert is first sharpened and then the drill body.

Bibliography

1. V.N. Feshchenko, Makhmutov R.Kh. Turning. Publishing house graduate School". Moscow. 1990.

2. L. Fadyushin, Ya.A.Musikant, A.I. Meshcheryakov and others. Tool for CNC machines, multi-purpose machines. M.: Mechanical Engineering, 1990.

3. PI Yasheritsyn et al. Fundamentals of cutting materials and cutting tools. Minsk: Higher school, 1981.

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Professionals who often use incisors to lathe when performing work on metal, as well as those who are involved in the sale of these products or the supply of machine-building enterprises, are well aware of what types of these tools are. For those who rarely encounter turning tools in their practice, it is quite difficult to understand their types, which are presented in a wide variety on the modern market.

Types of turning tools for metal processing

Turning tool design

In the design of any cutter used for, two main elements can be distinguished:

1. holder with which the tool is fixed on the machine;
2. working head, through which metal processing is performed.

The working head of the tool is formed by several planes, as well as cutting edges, the sharpening angle of which depends on the characteristics of the workpiece material and the type of processing. The tool holder can be made in two versions of its cross-section: square and rectangle.

By their design, cutters for turning are divided into the following types:

• straight - tools in which the holder, together with their working head, is located on one axis, or on two, but parallel to each other;
• curved incisors - if you look at such a tool from the side, you can clearly see that its holder is curved;
• bent - the bend of the working head of such tools in relation to the holder axis is noticeable if you look at them from above;
• drawn - for such cutters, the width of the working head is smaller than the width of the holder. The axis of the working head of such a cutter can coincide with the axis of the holder or be offset relative to it.

Classification of tools for turning

The classification of turning tools is regulated by the requirements of the corresponding GOST. According to the provisions of this document, incisors are classified into one of the following categories:

• one piece tool made entirely from. There are also cutters that are made entirely from, but they are rarely used;
• cutters, on the working part of which a plate made of hard alloy is soldered. Tools of this type are most widespread;
• cutters with removable carbide inserts, which are attached to their working head using special screws or clamps. Cutters of this type are used much less frequently compared to tools of other categories.

The incisors also differ in the direction in which the feeding movement is made. So, there are:

1. turning tools of the left type - during machining, they are fed from left to right. If you put your left hand on top of such an incisor, then its cutting edge will be located on the side of the bent thumb;
2. Right hand cutters are the most common tool type that feeds from right to left. To identify such a cutter, it is necessary to put on it right hand- its cutting edge will be located, respectively, on the side of the bent thumb.

Depending on what kind of work is performed on the turning equipment, the cutters are divided into the following types:

• for finishing works on metal;
• for rough work, also called roughing;
• for semi-finishing works;
• for performing delicate technological operations.

In the article we will consider the entire spectrum and determine the purpose and features of each of them. An important clarification: no matter what type of cutters belong to, certain grades of hard alloys are used as the material of their cutting plates: VK8, T5K10, T15K6, much less often T30K4, etc.

A tool with a straight tip is used to solve the same tasks as the bent cutters, but it is less convenient for chamfering. Basically, such a tool for (by the way, not widespread) is used to process the outer surfaces of cylindrical blanks.

Holders of such cutters for a lathe are made in two main standard sizes:

• rectangular shape - 25x16 mm;
• square shape - 25x25 mm (products with such holders are used to perform special work).

Such types of cutters, the working part of which can be bent to the right or left side, are used for machining the end part of the workpiece on a lathe. They are also used for chamfering.

Tool holders of this type can be made in different sizes(in mm):

• 16x10 (for training machines);
• 20x12 (this size is considered non-standard);
• 25x16 (the most common standard size);
• 32x20;
• 40x25 (products with a holder of this size are made mainly to order, they are almost impossible to find on the free market).

All requirements for cutters for metal for this purpose are specified in GOST 18877-73.

Such tools for a metal lathe can be made with a straight or bent working part, but they do not focus on this design feature, but simply call them continuous thrust.

A continuous thrust cutter, with the help of which the surface of cylindrical metal blanks is processed on a lathe, is the most popular type of cutting tool. The design features of such a cutter, which processes the workpiece along the axis of its rotation, allow even a single pass to remove a significant amount of excess metal from its surface.

Tool holders of this type can also be made in various sizes (in mm):

• 16x10;
• 20x12;
• 25x16;
• 32x20;
• 40x25.

This tool for a metal lathe can also be made with a right or left bend of the working part.

Outwardly, such a scoring cutter is very similar to a through cutter, but it has a different shape of the cutting insert - triangular. With the help of such tools, the workpieces are machined in a direction perpendicular to their axis of rotation. In addition to the bent ones, there are also persistent types of such turning tools, but their area of ​​application is very limited.

Cutters of this type can be manufactured with the following holder dimensions (in mm):

• 16x10;
• 25x16;
• 32x20.

The parting cutter is considered the most common type of tool for a metal lathe. In full accordance with its name, such a cutter is used for cutting workpieces at right angles. With its help, grooves of various depths are also cut on the surface of a metal part. Determining what is in front of you is a cutting tool for a lathe, it is quite simple. Its characteristic feature is a thin leg, on which a hard alloy plate is soldered.

Depending on the design, there are right- and left-sided types of cutting tools for a metal lathe. It is very easy to distinguish them from each other. To do this, turn the cutter with the cutting plate down and see which side of its leg is located. If it is on the right, then it is right-sided, and if on the left, then, accordingly, it is left-sided.

Such tools for a metal lathe also differ in the size of the holder (in mm):

• 16x10 (for small training machines);
• 20x12;
• 20x16 (the most common standard size);
• 40x25 (such massive turning tools are difficult to find on the free market, they are mainly made to order).

External threading tools

The purpose of such cutters for a metal lathe is to cut threads on the outer surface of the workpiece. Metric threads are cut with these serial tools, but you can change their sharpening and cut a different type of thread with them.

The cutting insert mounted on such turning tools has a spear-shaped shape, it is made from the alloys that have been indicated above.

Such cutters are made in the following standard sizes (in mm):

• 16x10;
• 25x16;
• 32x20 (used very rarely).

Such cutters for a lathe can only cut threads in a large diameter hole, which is explained by their design features. Outwardly, they resemble boring bits for processing blind holes, but they should not be confused, since they are fundamentally different from each other.

Such cutters for metal are produced in the following standard sizes (in mm):

• 16x16x150;
• 20x20x200;
• 25x25x300.

The holder of these tools for a metal lathe has a square section, the dimensions of the sides of which can be determined by the first two digits in the designation. The third number is the toolholder length. This parameter determines the depth to which you can cut a thread in the inner hole of a metal workpiece.

These cutters can only be used on lathes that are equipped with a tool called a guitar.

Blind hole boring bars

With boring cutters, the cutting plate of which has a triangular shape (as with scoring cutters), blind holes are processed. The working part of this type of tools is made with a bend.

Holders of such cutters can have the following dimensions (in mm):

• 16x16x170;
• 20x20x200;
• 25x25x300.

The maximum hole diameter that can be machined with such a turning tool depends on the size of its holder.

Boring bars for through holes

With such cutters, the working part of which is made with a bend, through holes, previously obtained by drilling, are processed. The depth of the hole that can be machined on the machine using this type of tool depends on the length of its holder. The layer of metal that is removed in this case is approximately equal to the amount of bend of its working part.

Boring cutters of the following standard sizes are presented on the modern market, the requirements for which are stipulated in GOST 18882-73 (in mm):

• 16x16x170;
• 20x20x200;
• 25x25x300.

Assembled cutters for lathes

Considering the main types of turning tools, one cannot fail to mention tools with a prefabricated structure, which are universal, since they can be equipped with cutting inserts for various purposes. For example, by attaching different types of inserts to the same holder, you can get cutters for at different angles.

In CNC machines, a general-purpose cutting tool is used, that is, a tool that is used on manually controlled machines. However, increased requirements are imposed on the tools intended for CNC machines in terms of rigidity, interchangeability, quality of sharpening, wear resistance, etc.

For fastening the tool, use tool holders and tool holders. The cutting tool is adjusted by measuring its position in the tool holder. If tool holders are fixed in the machine support or turret, then small-sized tool inserts are installed in them (Fig. 20.1).

In most modern machines, tool holders (Fig. 20.2) and cutting blocks (Fig. 20.3, a, b) are used to fix the cutting tool, since in this case there is no need for a special cutting tool. The most important requirements for cutting blocks are precise and stable positioning of the block in the support.

machine tool (installation error should be within 0.001 - 0.003 mm) and a small mass of the unit.

Rice. 20.1.Preset cutting insertsA:

H and V - height and width of the cutter, D - round cutter diameter

Rice. 20.2.

a - for the cutter, b- for boring bar, v- for a drill, G - for countersink

Rice. 20.3. Tool blocks without pre-dimensioning(a, 6)

Rice. 20.4.

• 1 - carbide plate, 2 - wedge,
• 3 - wedge clamp screw, 4 - locating pin, 5 - body, 6 - carbide backing,

H, H, B - constructive dimensions of the cutter

The setting surfaces of the cutting units are most often prisms and toothed racks.

CNC machines often use cutters with mechanical fastening multifaceted non-regrowth carbide plates (fig. 20.4).

The inserts on the holders are fixed with a wedge and a screw. Base the plates on the center hole with a 06 mm pin. Plates are distinguished by material, shape and size. In shape, the plates are characterized by the diameters of the circles circumscribed around the edges.

A feature of non-regrind plates (fig. 20.5) is that there is no need to sharpen them during operation. After blunting one cutting edge, the plate is unrolled and the other edge is put into operation. When the insert is rotated, the tip of the cutting edge will move (up to 0.2 mm) from the previous position. In this case, the adjustment of the initial position of the support is introduced on the machine control panel. Using position offsets, the dimensions (after processing) of the required quality (tolerance field) are obtained without removing the cutting block from the machine for adjustment in the fixture. It is possible to work with one bar, replacing only the carbide inserts.

The service life of the cutter plates can be significantly lengthened if you periodically refine their edges with a diamond file. The change in the size of the cutter after finishing is easily compensated for on a CNC machine using offsets. This makes the use of prefabricated cutters on CNC machines extremely efficient,

Rice. 20.5.

a, b- hexagonal shape with an angle of 80 "; v - triangular shape; rhombic shape; d , e - pentahedral shape; w, h- hexagonal shape; and- square shape

To process holes on CNC machines, drills, countersinks, reamers, both conventional and with a cylindrical shank, a leash and a screw to set their overhang, are used (Fig. 20.6).

Rice. 20.6.

a - drill, b - countersink

Rice. 20.7.

For finishing holes with a diameter over 20 mm, use boring bars with micrometric adjustment (fig. 20.7). The cutter 1 is mounted in the sleeve 3, in which it can perform a translational movement with the help of a nut-dial 2 relative to the mandrel 4

Tool change on CNC turret machines is automatic. In accordance with the control program, after the end of cutting, the tool is retracted from the workpiece, replaced, and then returned to the starting position. Moreover, first, the tool is quickly fed into the cutting zone, and then - feed at working speed.

To meet the requirements for the stability of the creation and operation of the cutting tool, it is necessary to observe the following conditions: maximum use of hard-alloy non-regrowth plates with mechanical fastening in the tool body; to use the most rational forms of plates, providing the possibility of processing with one cutter a large number surfaces; to unify the main and connecting dimensions of the tool (for example, the same connecting dimensions for cutters with the same angles in the plan), which creates convenience for programming technological operations; improve the precision of tool making.

When servicing CNC machines, use universal devices for setting the cutting tool to a size outside the machine. The devices have a base surface, on which an adapter for tool blocks and a sighting device are installed, moving relative to the base surface along two mutually perpendicular horizontal coordinates.

In order to achieve excellent productivity, excellent quality of processing parts, each cutting tool for CNC machines must meet certain requirements. Careful selection, preparation of the necessary tools, ensuring technical reliability, automation of the workflow of a CNC machine, includes the compliance of a high level of strength of such devices with their versatility.

For the production of cutting tools use:

• hard alloys;
• cermets;
• high-speed steel;
• synthetic materials.

Moreover, hard alloys, in turn, are also subdivided into several groups that differ in their operational, physical, and chemical properties:

• titanium-tantalum-tungsten;
• no tungsten;
• tungsten;
• tantalum-tungsten.

Basic requirements for cutting tools

Manufacturing machines with programmed control, as a rule, must use cutting attachments that satisfy a number of conditions, such as:

• stability of cutting properties;
• correct formation, implementation of the removal of shavings;
• versatility of use for processing different types of parts on different types of machines;
• their quick changeover for readjustment, processing of other parts or changing a blunt tool;
• ensuring the required accuracy of processing parts.

Attention. In some cases, the above requirements for cutting tools may not allow using on CNC devices those that are successfully used on conventional machines. For such modern machines, special groups of cutting, standardized devices are now allocated.

About tools used on lathes

For processing parts on turning devices, they usually use:

• incisors;
• different types of drills;
• sweep;
• taps.

On the features of using incisors

Most often, in a conventional lathe, special cutters are used as a special cutting tool, which have standard designs of the established type. Usually they are prefabricated, equipped with multifaceted special plates made of hard metals, various superhard materials (SMP).

Certain requirements are imposed on such incisors:

• maximum use of plates, which are mechanically fixed on their body to ensure constant, geometric, structural properties;
• the use of plates is the most optimal forms that will ensure the versatility of the tools;
• the ability to provide for all the actions of these devices in a straight or inverted position;
• to allow the possibility of the cutter of the left-hand design;
• guaranteeing high reliability of cutting inserts;
• correct shavings formation to divert them along special grooves made on the front sides of the used plates.

About the types of incisors

Typically, a set of cutting attachments used by such a CNC machine contains typical cutters of this type:

• walk-through, bent with right side by 45 ° to ensure chamfering, external turning of the end sides;
• cutters of a contour type with plates in the form of a parallelogram, which allow turning cylindrical, contour parts, turning conical parts up to 30 °;
• contoured, with special parallelogram-shaped plates for the ability to process hemispherical surfaces and cones up to 57 °;
• threaded, having rhombic plates, which are fixed from above, making it possible to cut threads, with a pitch distance from 2 to 6 mm.

About replaceable polyhedral plates (PMP)

Prefabricated cutters with SMP plates have gained the greatest popularity, their widespread use on machines with CNC, due to such factors as:

• economical consumption of scarce cutting tools;
• reducing the time for setting up tools, in which the change of the insert can be done without removing the cutter body;
• good quality of chip crushing;
• there is no need to constantly sharpen the cutter itself.

The dependence of the productivity of the cutting tool on the methods of fixing the plates

In prefabricated fixtures, productivity, as well as reliability, endurance, durability of their operation, depends on the methods of fixing the multifaceted plates. These fasteners must provide:

• reliability (without possible microscopic displacements during the movement produced by cutting tools);
• the density of contact of surfaces between the support plates and grooves;
• precise positioning and the ability to interchange working edges;
• support for geometric stability;
• crushing and reliable removal of chips;
• the shortest time allowed to change blades.

About tools used for milling machines

For milling, cutters are used as cutting devices, which come in various designs, and have special teeth for processing the surface of parts.

All milling tools differ in:

• the shape and appearance of the teeth;
• their direction and execution;
• their application and fastening.

In order to strengthen the cutter well in the chuck of the milling machine, use its shank, which is attached to the teeth by welding or with various fasteners, for example:

• bolts;
• special wedges;
• screws.

Sometimes the cutter can be represented as a single whole with its cutting part. So it is usually called - a solid cutter.

Important. Some modern CNC machines use only one-piece special end mills with cylindrical and conical shanks for a more durable, faster fixing in the chuck of milling machines.

In the production of milling tools, the following materials are most often used:

• cermets;
• fast cutting steels;
• hard alloys with special diamond spraying to increase hardness.

About the principles of milling

When milling with the help of the cutter teeth, chips are removed from the surfaces they grind, while it is removed from the cutting zone by special grooves along the cutter itself. Therefore, the location of the teeth relative to each other is of particular importance. Correct geometric mutual arrangement affects:

• cutting speed;
• the quality of the treated surfaces;
• wear resistance of the cutter;
• saving energy costs;
• the price of finished products.

Attention. Each type of presumed workpiece, be it wood, stone, metal, plexiglass, for example, requires a certain type of milling attachments.

About the types of cutters

These instruments are of various types, which are usually classified into certain groups, combined common feature... These signs include, for example:

• design features;
• geometric shapes;
• types of processed parts.

Design features include cutters:

• solid, made of one type of material as an indivisible whole with its cutting side;
• compound cutters, characterized by a gear part made of strong steel, brazed or welded to the shank;
• prefabricated, in which the toothed part is attached to the shank by a simple mechanical method (using bolts or screws).

According to the geometric type, such cutting devices include cutters:

• end;
• cylindrical type;
• end;
• conical shape.

A milling operation is associated with cutting actions performed on the surfaces of various parts, for example:

• grinding of surfaces;
• cutting grooves;
• cutting various types of threads;
• simple cutting of metal.

There are also typified cutting tools, depending on the type of workpieces being finished, for example, milling cutters for processing:

• copper, aluminum and other ductile metals;
• stone;
• wood;
• plexiglass;
• become.

In such cases, the material of the cutting parts themselves on the cutters depends on the rigidity of the workpiece being processed and, accordingly, on the design of special grooves for removing chips, which can be:

• plastic;
• small;
• large;
• fragile.

On the features of the selection of cutting tools

Nowadays it is difficult to imagine a modern CNC milling machine without correspondingly suitable special milling tools, without which significant productivity cannot be achieved. Precision processing of parts, ease of use - these are the main criteria for strict requirements imposed on them.

On such machines, cutting tools are often cylindrical end mills made of carbide or diamond materials. Their advantages include:

• possessing high wear resistance;
• the ability to resist vibration during rotational motion;
• increased rigidity;
• high cutting speed;
• very high accuracy processing.

All modern type machines with numerical control can perform the most complex technological operations, automatically performing the necessary processing of parts. Moreover, the parts can be made of cast iron, light metal alloys, steel. All actions of such devices are programmed even before the start of the working process. That is why it is so important to choose the right cutting tools that meet all the necessary requirements and parameters.