Turning cutters, bent through, with plates made of hard alloy. Design and dimensions

GOST 18877-73

GOST 18877-73 Group G23

INTERSTATE STANDARD

LATHE CUTS, PASSING, BENT, WITH CARBIDE ALLOY PLATES Design and dimensions Carbide-tipped bent bull-nose turning tools. Design and dimensions

ISS 25.100.10

Date of introduction 1974-07-01

ENTERED INTO EFFECT by Resolution of the State Committee of Standards of the Council of Ministers of the USSR dated June 8, 1973 N 1429 The validity period was removed by Decree of the State Standard of the USSR dated 02.20.81 N 866 INSTEAD OF GOST 6743-61 in terms of type 1; MN 575-64; MN 576-64; MN 5199-64 EDITION with Amendments No. 1, 2, approved in February 1981, November 1984 (IUS 5-81, 2-85), Amendments (IUS 6-88, IUS 4-89)

1. This standard applies to general purpose turning bent cutters with corners , , and soldered carbide plates. The standard fully complies with ST SEV 191-75.

2. The design and main dimensions of the cutters must correspond to those indicated in the drawing and table.

Damn.1

________________

*Dimensions for reference.

Dimensions in mm

An example of a symbol for a right-hand cutter with a cross-section of mm, with an angle of insertion of the plate into the rod of 0°, with a plate made of hard alloy grade T15K6:

Cutter 2102-0055 T15 K6 GOST 18877-73

1, 2. (Changed edition, Amendment No. 1, 2).

3. The insertion angle of the plate into the rod for processing cast iron and other brittle materials is 10°, for processing steel and other viscous materials - 0°. (Changed edition, Amendment No. 2).

4. (Deleted, Amendment No. 1).

5. Structural elements and geometric parameters of the cutters are indicated in Appendix 1.

6. The form of sharpening the front surface and finishing of the cutting part are indicated in Appendix 2.

7. Technical requirements - according to GOST 5688-61.

8. (Deleted, Amendment No. 2).

Damn.1

Damn.1

Table 1

Dimensions in mm

Damn.2

table 2

Dimensions in mm

APPENDIX 1. (Changed edition, Amendment No. 1, 2).

Classification

According to the design and principle of operation, this tool is differentiated into the following options:

• Straight models with cutting edges parallel to the holder axis are characterized by the absence of bends. They are designed for rough processing, which involves removing a significant amount of material, often in several passes, when turning unnecessary fragments of parts.
• Bent scoring cutters have a similar purpose, but are designed for processing objects of more complex shapes: bending allows you to grind hard-to-reach places, etc. The cutting edges of such models are inclined from the axis of the holder. The method of work is determined by the characteristics of the tool and the type and thickness of the material.
• Turning stop options are designed for turning objects of low rigidity. They are used for trimming edges and turning stepped surfaces. This is the most common type of instrument considered. Their cutting edges are parallel to the holder axis, however, in comparison with straight scoring cutters, they have a smaller angle.

Based on the feeding direction, these tools are classified into left-handed and right-handed.

Finally, scoring cutters are differentiated according to production technology.

• One-piece options include head and holder made from the same material.
• Composite models have elements of different composition.

Thus, bent scoring cutters with carbide cutting inserts are described by GOST 18880-73. For turning cutters equipped with super-carbide inserts, and similar scoring models, the characteristics are defined in GOST 28990-91. GOST 18871-73 defines the features of end options with high-speed steel plates. GOST 29132-91 defines the parameters of models with multifaceted replaceable inserts of the through-turning, copying and scoring types. GOSTs provide drawings of scoring cutters, types and sizes of these tools.

Drawing

Table 1

2. Finish the front and rear surfaces along the main cutting edge and along the radius. 1, 2. (Changed edition, Amendment No. 1, 2).

3. To strengthen the tip of the cutter and better heat dissipation, it is recommended to sharpen the auxiliary plane at an angle of 15° over a length of 3 ... 5 mm.

table 2

mm

Table 3

mm

________________

* Diameters of the drawn part of the boring cutters. ** The text corresponds to the original. — Note.

4. The geometric parameters of the cutting parts of the incisors when sharpening and finishing them with diamond wheels are indicated in Figure 2.

Selecting a beveled cutter

The choice of the necessary tool depends on the following requirements that are presented in the manufacture of a particular part. These requirements include:

• type of processing (finishing, semi-roughing, roughing, high-precision processing);
• tool feed directions (right or left);
• the nature of cutting or removing a layer (passing, thrust, scoring, threading);
• holder length;
• type of tip (solid, welded, removable);
• shape of the cutting element (triangular, rectangular, special design).

Depending on the complexity of the problem being solved, a bent cutter is selected that is capable of high-quality processing on a specific type of machine. The most universal is considered to be a bent through cutter with replaceable plates. The exact purpose of a particular instrument is determined by the accepted standard and indicated on the marking. The bent cutter T15k6 is used for surface treatment of parts made from various grades of steel, including alloyed ones. Alloy VK8 is used for roughing work, drilling, processing of internal surfaces, and milling. The variety of types of structures requires their evaluation according to the criterion of efficiency - cost. It is this that affects the final price of the manufactured part.

Tips for choosing

Bent-through turning devices can be created in several variations, which will vary in size, material, and some other parameters

When choosing a cutter, you should pay special attention to what kind of workpieces you will have to deal with. If a wider range of parts is used in the production process, then you need to have not one curved cutter, but a real set for use in various cases

The overall size of the product must be selected in accordance with the size of the workpiece itself. The most widely used option will be the medium one, which will not require constant replacement for a large number of jobs with different types of products. Recommendation from experts: regular replacement of cutters can lead to large losses of time in the process of creating work and to equipment downtime, so you need to decide in advance on the most optimal option.

Prefabricated cutters for lathes

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

Prefabricated cutters

As a rule, such cutters are used on CNC machines or on special machines and are used for contour turning, boring blind and through holes and other specialized work.

Operating rules

Turning cutters are capable of performing their main function for a long time until the working surface is ground down. But improper use will shorten the life of the tool. To prevent preliminary wear, you need to follow simple operating rules:

• Install centrally.
• The larger the dimensions of the workpiece, the larger the cutter should be.
• Turn on cooling when operating in heavy conditions.
• Sharpen in a timely manner.
• Periodically polish the working surfaces with a fine-grained stone without removing the tool from the tool holder.
• Apply the tool to the workpiece manually, and after touching, turn on the automatic feed.
• When stopping the machine, first manually retract the tool, then turn off the unit.
• Select the correct cutting modes.
• Do not store the tool in a pile - this will lead to chips and cracks on the cutting edge.
• When working with a cutting tool, bring it as close to the chuck as possible.

Many types of work are performed on a lathe. A separate cutter is provided for each process. It is selected based on the material being processed, cutting conditions, cleanliness and roughness parameters. The tool must be sharpened in a timely manner, and the rules of operation and storage must be followed.

What is a lathe scoring tool used for?

There are 8 types of cutters in total: pass-through, boring, cutting-off, slotting, chamfering, shaping and scoring. Each of them is used in specific operations. For example, parting cutters are designed to separate finished products from workpieces, and boring cutters are designed to bore holes or create internal chamfers. But the scoring cutter has a wider application. Almost every basic operation on a lathe is performed using this tool. With its help, you can cut ledges at right or acute angles, create external chamfers, grind the end and any other external surface of a cylindrical part. Thus, it is one of the most important tools, as it directly influences the initial formation of the finished product.

Cutting modes

The process of operating through cutters is quite simple. Depending on the shape of the workpiece and the processing method, the direction of movement is chosen: longitudinal or transverse.

Please note the purpose of the tool: tools for roughing are prohibited from being used for finishing work and vice versa. It is also prohibited to change the established order of work:

It is also prohibited to change the established order of work:

1. First of all, rough work is performed, which is characterized by a deep degree of impact: during processing, it is possible to remove up to 5 millimeters of metal in several passes.
2. Finishing work is carried out in order to comply with the exact parameters of the product. The thickness of the cut metal should not exceed tenths of a millimeter.

Passing cutters are an indispensable tool for processing the metal surface of rotating elements. The types of work depend on the shape and structure of the devices. Have you observed the process of external processing of parts? Some turners believe that domestic cutter manufacturers are not inferior to famous foreign companies, including the German manufacturer Optimum. What do you think about this? Express your opinion in the comments section.

Plan angles

For a cutting tool, they have the following names of plan angles:

• main angle;
• auxiliary;
• corner located at the apex.

The first is formed between the plane of the edge projection and the main plane of the tool.

The second is determined between the continuation of the projection of the cutting edge with a plane directed along the movement of the workpiece.

Cutter angles in plan

The third is between the first listed plane and the main plane.

The numerical values ​​of the parameter located at the vertex can take positive and negative values. It turns out positive when the top of the sharpening point is at the lowest point of the workpiece. Minus sign - the peak reaches its highest point.

Wood cutters for a lathe: purpose and design of elements

The main purpose of wood turning tools is manual processing of a part rotating in a special machine. The lathe used for these purposes is designed to impart rotation to the body. Wooden blanks, which are initially round in shape, are mounted on a lathe using two clamps. One clamp is connected to an electric motor, which sets the part in motion.

The choice of the type of turning cutter, its sharpening and condition largely determines the possibility of certain operations and the manufacture of parts of the required configuration

Important! On the motor side, the fixation must be rigid so that rotational movements do not occur at idle. The cutters, which are fixed to the rotating mechanism, perform processing of the rotating body. Depending on the strength, shape and sharpness of the cutter, marks are formed on the wooden workpiece

This also determines the shape of the workpiece

Depending on the strength, shape and sharpness of the cutter, marks are formed on the wooden workpiece. This also determines the shape of the workpiece

The cutters, which are fixed to the rotating mechanism, perform processing of the rotating body. Depending on the strength, shape and sharpness of the cutter, marks are formed on the wooden workpiece. This also determines the shape of the workpiece.

The design of a lathe cutter consists of a working metal part and a wooden handle. The working element conventionally consists of a blade, body and shank. The blade consists of a front, back and pointed angle. The size of the sharpening angle depends on the material of the workpiece. Most often, craftsmen use sharp corners when working with wood. The body is the main part for which the turner holds the cutter on the armrest of the machine with his non-working hand. The shank is a narrowed part into which the body of the tool goes. It is on this that the handle of the turning tool is attached.

The handle structure consists of a base and a neck. The base is the larger part of the handle that the turner holds with his hand. The neck is represented by a small cylindrical part with a metal fastening ring. It is designed to prevent the handle from cracking while being pressed onto the shank of the working part.

Wood turning tools consist of a back corner, a pointed corner and a rake corner.

Cutting modes

A turning type through cutter can be used in a fairly simple operating mode. They can make longitudinal as well as transverse movements, depending on the profile of the part and its processing.

It is worthwhile from the very beginning to carry out the rough processing process with only one device, which will be intended specifically for this purpose, and then create a cleaner pass over an almost finished type of surface. If during the roughing process the total thickness of up to several millimeters will be removed over time, then during finishing this figure goes up to tenths in several passes.

Markings used

The quality of purchased scoring cutters must meet the requirements specified in GOST 18871-73, 18880-73, 28980-91, 29132-91 and the technical specifications of manufacturing companies, if they are manufactured according to such a document. These standards indicate the design features of products, differences in geometry and dimensions. The marking of scoring cutters depends on their type. The table shows the marking features

Selection criteria

Despite the fact that turning cutters are considered consumable elements of a lathe, their choice, like the choice of any other tool, should be approached responsibly. A correctly selected turning tool will allow longer operation and better processing of products. First of all, it is worth considering what work will be performed.

If the range of work is quite wide and includes processing different types of parts, then it is worth stocking up on not just one type of cutter, but several at once. It is preferable to purchase a set of cutters. This way you will be as calm as possible in the event that you do not have the cutter you need on hand.

Also, you should take into account the size of the workpiece being processed. The choice of cutter size also depends on the size of the workpiece. Most often, a medium-sized incisor is purchased. They are more versatile and allow you to work with various products without requiring replacement.

Another selection criterion should be the material used to make the tool. When the workpiece is made of soft and unhardened metal, cutters are chosen, the material for which is high-speed steel.

In cases where processing will take place on hard materials, I use cutters made of carbide materials. Such cutters are resistant to vibration vibrations and temperature changes, and their service life is much longer.

When sharpening is required

There are two cases in which it is necessary:

• the edge has worn out and lost its useful qualities;
• a new tool is released.

In both cases, it must be carried out, otherwise you simply will not be able to process the part with the required accuracy and ensure the required surface quality. Plus, during the process, the workpiece will probably additionally suffer from beating and vibration.

So be sure to do it when it is required, that is, regularly and in a timely manner; Thus, you will provide the blade with the necessary sharpness and reliability, which will have a positive impact on the overall level of safety of technological operations on the machine.

Rules for sharpening

1. use only a suitable abrasive wheel;
2. work with gloves and a mask (goggles), do not forget about protection;
3. clean all the main parts and elements of the turning cutter from dust and dirt and fix it in the tool rest, adjusting the position;
4. first of all, remove the rear corners and only after measuring and checking them, proceed to the front ones;
5. do not neglect fine-tuning - it is needed in every area where even the smallest irregularities are observed.

Tools used

The base in this case is a pair of grinding wheels: one is made of green silicon carbide, the other is made of electrocorundum. The first is suitable for materials with a high degree of hardness, the second for softer tool steels.

You will also need a grinding machine for finishing operations. Since the latter are considered thin, the equipment must operate at low speeds with the lowest possible level of runout. A diamond or CBN surface is suitable as an abrasive.

Advantages and disadvantages

It is quite difficult to determine the pros and cons of such a product. First of all, its versatility in operation will be an undoubted advantage. With this tool you can perform many types of actions (rough and fine finishing, thread formation, trimming of various parts, and many others).

The downside of such a tool is its expense. Turning cutters are primarily consumables and during operation they often break, grind down and become unusable. Therefore, before performing any turning activities, you should stock up on tools for future use.

Tool Options

Any of them consists of two structural elements. This is a holder responsible for high-quality fixation in the machine, and a working head that directly removes excess layers of material.

And each of them has three turning tool surfaces:

• the front one is responsible for chip collection;
• main (primary) and auxiliary (secondary) rear ones, facing the workpiece.
• The intersections form the edge and form the apex, that is, the sharpest point experiencing maximum loads. To prevent it from chipping, it is slightly rounded to improve durability (introducing the concept of radius into the technical documentation) or, alternatively, a straight transition is made.

But there are also parameters whose role is even more important, because they determine the relative position of all three planes. These are angles, the calculated values ​​of which depend on a number of factors, and in the list of key ones:

• operating conditions and intensity;
• instrument material;
• hardness, viscosity and other quality characteristics of the workpiece.

They need detailed consideration.

Making your own cutters: a step-by-step guide

The main thing is to use only tool steel that has sufficiently high performance characteristics.

Selecting the required configuration of files or rasps

The selection of these parts will be easier if the owner knows in advance exactly what tasks he faces. After this, choosing the length, shape and size will not be difficult. Here are some tips.

• If you need to file up to 5-10 mm in thickness, it is better to stop at cut number 0 or 1.
• The processing accuracy should be within 0.01-0.02 mm.
• It is much easier to choose devices based on length.

The main guideline is the dimensions of the surface that needs to be sawed. The larger this parameter, the larger the device itself should be.

You can use a specific formula to make the calculation more accurate. We add 15 cm to the length of the surface of the product. We get the value, which will be the length of the working surface of the file or rasp. The main thing is that when working, the tool is passed over the entire workpiece.

Fastening cutting parts

Homemade tools do the same as professional ones. The optimal solution is self-tapping screws. The higher quality the product, the better.

Only regular sharpening of the cutters will allow you to obtain the most accurate results. The need for the procedure arises not only for instruments that have disposable carbide inserts. The work is performed by specialized machines when it comes to large-scale manufacturing enterprises.

There are practically no restrictions on the method for home use. Suitable for use with conventional sharpening wheels and chemically active reagents. Machines for universal, specialized purposes are a cheap option that maintains efficiency.

When processing the back of a tool, there are three main stages.

1. Maintaining the same angle as the holder itself at the back. The increase in the indicator compared to the rear cutting angle is 5 degrees.
2. The second stage involves processing the surface of the cutting insert itself from the back. Here we need to keep the excess equal to 2 degrees.
3. Finishing is the third stage. It is needed to form the required rear angle.

The front surface also goes through several processing stages.

Refinement and polishing

This is done with carbide on a special cast iron disk. The device rotates, maintaining a speed of up to 1-2 m/s. The direction of rotation of the disk itself is towards the working edge, away from the supporting part of the tool.

Consistently grind the blades and tool surfaces. The incisors are almost brought to a shine, and any irregularities are removed.

Why is fine-tuning needed? A tool becomes dull and wears out over time if it is used often enough. The reason is that the plate rubs against the workpieces and chips. If the plate is smoother, there will be less friction. In this situation, tool wear slows down.

The finishing process has other features:

• When finishing, abrasive pastes are used, the main component of which is boron carbide.
• Finishing involves wetting the tool with kerosene.
• Then the paste is applied to the surface in a zigzag manner.
• The instrument is brought to the disk.
• GOI paste can be used in conjunction with kerosene.
• Kerosene is not a mandatory step when using modern lubricants.

It is important to install the support table correctly. After its installation, in comparison with the middle part of the disk, the cutter blades with the part are on the same lines, or lower. Rotation of the disk - towards the threaded plate, directed

The rotation of the disk is directed towards the threaded plate.

The paste particles begin to be crushed when the tool is pressed and finishing is started. The cutter has no chips or abrasions when passing through the edges. Irregularities on the incisal surface are eliminated thanks to the very grains of the paste.