Metal cutting tools and fixtures

Abrasive tools for metal processing

These metal working tools differ in their shape and configuration, but the principle of operation is exactly the same as that of the previous class.

Abrasive tools are used for grinding, polishing and other types of surface treatment of workpieces, in order to change their size, degree of roughness, or fit.

Abrasives can be linked together, then they have the form of bars or circles, which are built into machines, or used separately.

They can also be plastic, namely, glued to a soft surface, such as leather or fabric. These tools make it easier to handle uneven surfaces of parts.

There are abrasives with fine and coarse crystals, each of which can be used for both roughing and finishing, depending on the requirements for the finished product.

Cutting tools for metal processing

This type of tool is used for making through or blind holes in metal, tapping and other operations that are necessary to give the workpiece the desired shape and size. The peculiarity of such devices is that they are made of very resistant materials, the strength of which is higher than the strength of the metals being processed.

For the manufacture of cutters, alloyed high-speed and tool steels, as well as hard alloys, are chosen. All cutting tools are similar to each other, they are wedge-shaped.

The tip enters the workpiece after applying pressure, and under the influence of movement begins to remove its top layer, forming and folding chips.

It is worth noting that during the process, friction occurs between the cutter and the workpiece, during which the cutting element heats up.

As you know, some metals and alloys can lose their strength when heated, it is for this reason that hardened materials are used for the manufacture of tools, which do not lose their hardness and cutting ability when the temperature rises.

What tool is more appropriate to use in everyday life and in production

Since tools for metal processing can be mechanical and automatic, it is worth taking a very responsible approach to their choice.

At home and in small private workshops, it is advisable to use simple installations that do not differ in high productivity, but also do not cost quite a lot. Such a choice will be the most optimal, since it will allow performing all processes in small volumes, and not investing initially large sums in the purchase of equipment.

Serial and mass production must be equipped with dedicated high-performance aggregates that can create the most accurate and complex parts.

The ideal option for factories will be machines that can be controlled using software, such machines are distinguished by high speed of execution of all tasks, functionality, excellent performance and accuracy.

With installations of this type, the receipt of defective products is practically excluded and the use of human labor is minimized. The units can work both independently and in an automated mowing line, which is especially convenient for large-scale enterprises.

Metalworking tools

Metal blanks are processed both in everyday life and in industrial production. Surely, each of us has come across sharpening of knives, scissors and other cutting household items, all these processes are carried out using special devices such as bars, grinding wheels or musats.

In the conditions of factories producing metal parts and products, these processes are not performed manually, but with the help of special equipment, which allows, by removing the top layer of the material, to give it the required shape and size.

The workshops use a variety of tools for metal processing, they all have some differences among themselves, but the principle of operation remains the same: when some force is applied, the cutting element removes the top layer of metal, which turns into shavings.

Let’s consider in more detail what types of tools are used to equip the units, and what functions they perform.

Types of metalworking tools:

  • Incisors;
  • Cutters;
  • Countersinks;
  • Sweep;
  • Broaches;
  • Taps;
  • Grinding wheels, skins, stones.

All these tools for metal processing can be conditionally divided into two classes: cutting and abrasive. Let’s take a closer look at each class.

Where to find out about the latest in metalworking tools

Innovative solutions from leading world leaders who create installations, technologies and tools for metal processing will be presented at the specialized exhibition “Metalworking”.

The international event will take place at the Moscow Expocentre Fairgrounds. The exhibitors will be representatives of more than 1000 domestic and foreign companies that are actively involved in research and development in the field of metalworking.

Guests will be able to get acquainted with the latest technical achievements of the best specialists, and purchase for themselves the latest units that are suitable for equipping factories and private workshops.

Metal straightening tools

The straightening technological operation removes various types of workpiece defects. Each of them is suitable for a certain type of tool, fixtures and technological methods.

Understanding Cutting Tool Geometry

List of devices used for straightening, straightening and bending

Manual straightening is carried out both with standard tools and devices, and made exclusively for this particular workpiece. Therefore, the list of such equipment is diverse, below are only some types.

Ironers

It is not recommended to edit thin sheet metal by percussion method; here the burnishing technology is used. The key role is played by a tool in the form of a wooden or metal bar called a trowel. The workpiece is placed on a leveling plate and the metal is pulled from the beginning of the unevenness to the edge of the workpiece with the help of ironing tools. Thus, the bulge of the leaf disappears.

Types of workpieces

All types of rolled products can be eliminated from defects by deformation methods. Waviness, warping, folds on the sheets are quite common; it is necessary to straighten the wire from the coils for use in the technological process. Profile pipes and other workpieces of this configuration need to return straightness and eliminate twisting around the longitudinal axis.

In the production process of the finished part, it is necessary to apply the technological operation of straightening to eliminate the residual deformations that occur at the intermediate stages of the technology, for example, after welding, cutting, punching.

Correct cast iron and steel plates

One of the most important hand straighteners is the correct plate. It eliminates defects in sheet and strip blanks, deflections on bars, pipes and other profiles.

A metal straightening workstation equipped with a straightening plate must be shock-resistant. Therefore, the slabs are quite massive and are often made of heavy ingots of gray cast iron with the largest linear dimensions up to 4.0 meters and even more. High requirements for flatness are imposed on the base surface of the slabs, they are planed and ground by the final operations and installed on a horizontal level.

Straightening headstock

Some manufacturing processes for parts include straightening pre-heat treated workpieces. These blanks have a certain surface hardness, which creates specific requirements for the dressing tool. In the hardened state, the workpiece is straightened with stricter tolerances from the nominal dimensions, such straightening is called in another way straightening.

To locate the workpieces, straightening headstock are used, which are made from steel workpieces with m carbon, which allows hardening with high hardness. To give the workpiece a greater degree of freedom during straightening, the surface of the headstock is cylindrical or spherical.

Sledgehammers

Hammers are used for rough dressing of large workpieces when the impact force of a conventional hammer is not enough. The striker of increased weight (up to 5 kg.) Has a deforming effect on round and profiled steel of large cross-section.

metal, cutting, tools, fixtures

Sledgehammer 2000 grams with fiberglass handle Gigant SLH20.

Tools and devices used for cutting

Methodical instructions for laboratory studies in the discipline “Fundamentals of repair and diagnostics of oil and gas equipment”

The instructions describe the tools and devices used in cutting, the basic rules for performing work when cutting metal, as well as the rules for cutting metals for students of specialty 130602 Machinery and equipment of oil and gas fields are given.

Compiled by: Sidorkin D.I., Assistant, Candidate of Engineering Sciences

Reviewer Ishemguzhin I.E., Associate Professor, Candidate of Engineering Sciences

© Ufa State Petroleum Technical University, 2007

3 Tools and devices used for cutting

4 Rules for performing work when cutting materials

The purpose of this laboratory work is to consolidate and deepen the practical knowledge of students on the tools used in cutting metal and methods of performing these works.

Cutting. This is an operation associated with the separation of materials into parts using a hacksaw blade, scissors and other cutting tools. Depending on the tool used, cutting can be carried out with or without chip removal.

Tools and devices used for cutting

The most widespread is the cutting of metals with hand-held metal saws and scissors. Hand lever and guillotine shears are used to cut sheet and bar material.

Hand-held locksaw hacksaws are intended mainly for cutting section and profile rolled metal by hand, as well as for cutting thick sheets and strips, cutting grooves and slots in screw heads, cutting workpieces along the contour and other works, cutting is performed using hacksaw blades, which are made of carbon (grade P9 or P18) or alloyed (grade X6VF) tool steel and hardened after cutting the teeth. The most common hacksaw blades are 13 and 16 mm wide with a thickness of 0.5 to 0.8 mm and a length of 250.300 mm. To carry out cutting, the blade is installed in a special hacksaw machine. Hacksaw machines are of two types: solid and sliding, allowing you to install a hacksaw blade of different lengths in the machine.

One-piece hacksaw (Figure 1) consists of a machine 7, a tension screw with a wing nut 6 and a handle 2. The hacksaw blade 4 is installed in the slots of the heads 5 and fixed with pins 3.

machine; 2. handle; 3. pins; 4. hacksaw blade; 5. head of attachment of the hacksaw blade; 6. tension screw with nut

The sliding hacksaw machine (Figure 2) differs in that it consists of two parts, connected by a clip. The holder is rigidly attached to one half of the machine, and the other half can change its position along the length by installing a pin pressed into it, which is fixed in special grooves of the holder.

Figure 2. Sliding hacksaw

On one side of the hacksaw blade, teeth are cut along the entire length (Figure 3, a). Each tooth of a hacksaw blade is given the shape of a cutting wedge, which is characterized by certain geometric parameters: clearance angle α, taper angle β, rake angle γ and cutting angle δ. There are dependencies between the angles characterizing the geometry of the cutting wedge of the hacksaw blade teeth: α β β = 90 °; α β = δ.

a. geometric parameters of the hacksaw blade: γ. rake angle; α is the back angle; β is the angle of sharpening; δ. cutting angle; b. wiring on the tooth; c. wiring along the canvas

Since the work (movement) of the hacksaw blade is carried out in a limited space, to prevent it from jamming during operation, the teeth of the hacksaw blade must be divorced. Depending on the size of the pitch of the teeth, that is, on the distance between two adjacent teeth, a tooth setting (Figure 3, b) and a setting along the blade (Figure 3, c) are distinguished. The spreading along the tooth is made on the canvases with a large step, in this case, each tooth of the hacksaw blade is alternately bent one way or the other. When spreading along the canvas, first bend two or three teeth in one direction, and then two or three teeth in the other. In this case, a wavy line appears along the canvas.

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When installing the blades in a hacksaw machine, you must ensure that the correct direction of the tooth is selected. The edge of the cutting wedge must always be directed towards the working movement of the blade. forward, in the direction from the handle to the thumbscrew of the tensioning screw. The second prerequisite for normal operation when cutting is the tension of the hacksaw blade. The tension should be such that the blade does not undergo elastic deformations during cutting and at the same time should not be too strong, as this can lead to breakage of the blade during operation, even if it is slightly skewed.

Manual scissors (Figure 4) are available as right and left. On the right scissors, the bevel on the cutting part on each of the halves is on the right side, and on the left. from the left. Manual scissors can cut sheet steel up to 0.7 mm thick, roofing iron up to 1.0 mm thick, copper and brass sheets up to 1.5 mm thick.

a. right; b. with curved blades; c. finger

Such scissors (Figure 4, a) are designed to cut material along a straight mowing line or along an arc of a large radius. If you want to cut a hole in the sheet material or cut a part along a contour with small radii of curvature, use scissors with curved blades (Figure 4, b) or finger scissors with thin and narrow cutting blades (Figure 4, c).

All scissors, regardless of their design, are based (like other cutting tools) a cutting wedge. The shape of the scissors cutting wedge is characterized by the following geometrical parameters (Figure 5): angle of taper β; back angle α, providing a decrease in friction when working with scissors and constituting 2.3 °. In order to reduce the forces applied during cutting, the cutting knives are set at an angle φ (the larger this angle, the lower the cutting force). With an increase in this angle, forces are created that push the sheet out from under the knives, in connection with this, the value of the angle φ is selected in the range of 7. 12 °, which creates optimal conditions for cutting. The taper angle β is selected depending on the material to be processed (the harder the material, the larger this angle should be). For soft metals and alloys (for example, copper, brass), it is 65 °; for metals of medium hardness. 70. 75 °, and for solid materials. 80 °. If it is required to cut sheets of large thickness (up to 2.0 mm), use chair scissors (Figure 6). These scissors have one handle with a downward-bent end; with this pointed end, the scissors are fixed in a wooden block or vise. The second handle is used for pressing and actually cutting.

α is the back angle; β is the taper angle; φ. the angle between the blades

Figure 5. Geometric parameters of the scissors blades

A good effect when cutting sheet steel up to 2.5 mm thick can be achieved using power shears (Figure 7). During operation, the handle 4 with a notch is fixed in a vice, and the handle 5 with a plastic tip is grasped with the right hand. Working handle 5 is a system of two levers connected in series. The first lever 7 ends with a knife 1 and is connected by a screw 2 through a washer 8 to the handle 4. The handle 5 is also connected to the handle 4 through the axle 6 and the articulated link 3. This system of levers provides an increase in the cutting force approximately twice as compared to conventional scissors of the same dimensions.

Tabletop manual lever scissors (Figure 8) are used to cut sheet steel up to 4 mm thick, aluminum and brass. up to 6 mm. The base 1 of the scissors is bolted to the workbench. The handle 2 provides a reciprocating movement of the knife 3. The second knife 4 is fixed in the base body 1. The sheet to be cut is placed on the shelf of the fixed knife and, moving the movable knife 3 with the handle 2, the sheet is cut along the marking risk. Lever scissors may differ slightly from each other in design, but the principle of their operation is the same in all cases.

knife; 2. screw; 3. hinge link; 4. knurled handle; 5. handle with a plastic tip; 6. axis; 7. lever; 8. washer

Figure 8. Desktop manual lever scissors

Pipe cutters (Figure 9) are used for cutting pipes of various diameters instead of a hacksaw, as well as for better cutting pipes. The pipe cutter is a special device in which steel disk cutters-rollers serve as the cutting tool. The most common pipe cutters are roller, clamp and chain cutters.

The roller pipe cutter (Figure 9, a) consists of a bracket 4, a screw lever 3 and three disc cutting rollers 6, two of which are mounted on the axles in the bracket 4, and the third is mounted on an axis fixed in a movable bracket 5

a. roller: 1. clamp; 2. screw; 3. screw lever; 4. bracket; 5. bracket; 6. cutting edges; 7. pipe; b. clamp; в. chain; g. incisal: 1. pressure screw; 2. cutting tool; 3. screw

The pipe to be cut is fixed in the clamp 1 with the screw 2, after which the pipe cutter is installed on the pipe 7. When the screw lever 3 is rotated to the right, the bracket 5 will move the cutting roller 6 until it touches the pipe wall under some pressure. A pipe cutter with three rollers cuts in three places at the same time, therefore, when working, it is slightly swayed with a lever (about one third of a turn in each direction). To improve the quality of cutting, the cutting site is lubricated with oil.

To cut pipes of large diameter, clamp or chain pipe cutters are used (Figure 9, b, c).

When cutting with roller pipe cutters, its end is pressed into the pipe, which leads to the formation of burrs and the need for further processing of the pipe to remove them. This drawback can be eliminated by an incisal pipe cutter (Figure 9, d), in which the rollers perform only the function of centering the pipe in the device, and cutting is performed with a cutting cutter 2, which, as it plunges into the pipe, is fed by a pressure screw 7. The rollers are pressed using a screw 3.

Tools and devices used for cutting

for laboratory studies in the discipline “Fundamentals of repair and diagnostics of oil and gas equipment”

The instructions describe the tools and devices used in cutting, the basic rules for performing work when cutting metal, as well as the rules for cutting metals for students of specialty 130602 Machinery and equipment of oil and gas fields are given.

Compiled by: Sidorkin D.I., Assistant, Candidate of Engineering Sciences

Reviewer Ishemguzhin I.E., Associate Professor, Candidate of Engineering Sciences

© Ufa State Petroleum Technical University, 2007

3 Tools and devices used for cutting

4 Rules for performing work when cutting materials

The purpose of this laboratory work is to consolidate and deepen the practical knowledge of students on the tools used in cutting metal and methods of performing these works.

Cutting. This is an operation associated with the separation of materials into parts using a hacksaw blade, scissors and other cutting tools. Depending on the tool used, cutting can be carried out with or without chip removal.

Tools and devices used for cutting

The most widespread is the cutting of metals with hand-held metal saws and scissors. Hand lever and guillotine shears are used to cut sheet and bar material.

Hand locksaw hacksaws are intended mainly for cutting bar and profile steel manually, as well as for cutting thick sheets and strips, cutting grooves and slots in screw heads, cutting workpieces along the contour and other works, cutting is performed using hacksaw blades, which are made of carbon (grade P9 or P18) or alloyed (grade X6VF) tool steel and hardened after cutting the teeth. The most common hacksaw blades are 13 and 16 mm wide with a thickness of 0.5 to 0.8 mm and a length of 250.300 mm. To carry out cutting, the blade is installed in a special hacksaw machine. Hacksaw machines are of two types: solid and sliding, allowing you to install a hacksaw blade of different lengths in the machine.

One-piece hacksaw (picture 1) consists of machine 7, tension screw with wing nut 6 and handles 2. Hacksaw blade four installed in the slot of the heads five and fix it with pins 3.

machine; 2. handle; 3. pins; 4. hacksaw blade; 5. head of attachment of the hacksaw blade; 6. tension screw with nut

Sliding hacksaw (Figure 2) differs in that it consists of two parts connected by a clip. The holder is rigidly attached to one half of the machine, and the other half can change its position along the length by installing a pin pressed into it, which is fixed in special grooves of the holder.

Figure 2. Sliding hacksaw

On one side of the hacksaw blade, teeth are cut along the entire length (Figure 3, but). Each tooth of a hacksaw blade is given the shape of a cutting wedge, which is characterized by certain geometric parameters: clearance angle α, taper angle β, rake angle γ and cutting angle δ. There are dependencies between the angles characterizing the geometry of the cutting wedge of the hacksaw blade teeth: α β β = 90 °; α β = δ.

a. geometric parameters of the hacksaw blade: γ. rake angle; α is the back angle; β is the angle of sharpening; δ. cutting angle; b. wiring on the tooth; c. wiring along the canvas

Since the work (movement) of the hacksaw blade is carried out in a limited space, to prevent it from jamming during operation, the teeth of the hacksaw blade must be divorced. Depending on the size of the pitch of the teeth, that is, on the distance between two adjacent teeth, a tooth setting is distinguished (Figure 3, b) and routing along the canvas (Figure 3, in). The spreading along the tooth is made on the canvases with a large step, in this case, each tooth of the hacksaw blade is alternately bent one way or the other. When spreading along the canvas, first bend two or three teeth in one direction, and then two or three teeth in the other. In this case, a wavy line appears along the canvas.

When installing the blades in a hacksaw machine, you must ensure that the correct direction of the tooth is selected. The edge of the cutting wedge must always be directed towards the working movement of the blade. forward, in the direction from the handle to the thumbscrew of the tensioning screw. The second prerequisite for normal operation when cutting is the tension of the hacksaw blade. The tension should be such that the blade does not undergo elastic deformations during cutting and at the same time should not be too strong, as this can lead to breakage of the blade during operation, even if it is slightly skewed.

Hand scissors (Figure 4) are right and left. On the right scissors, the bevel on the cutting part on each of the halves is on the right side, and on the left. from the left. Manual scissors can cut sheet steel up to 0.7 mm thick, roofing iron up to 1.0 mm thick, copper and brass sheets up to 1.5 mm thick.

a. right; b. with curved blades; c. finger

Such scissors (Figure 4, but) designed for cutting material in a straight line or in a large arc. If you want to cut a hole in sheet material or cut a part along a contour with small radii of curvature, use scissors with curved blades (Figure 4, b) or finger scissors with thin and narrow cutting blades (Figure 4, in).

All scissors, regardless of their design, are based (like other cutting tools) a cutting wedge. The shape of the scissors cutting wedge is characterized by the following geometrical parameters (Figure 5): angle of taper β; back angle α, providing a decrease in friction when working with scissors and constituting 2.3 °. In order to reduce the forces applied during cutting, the cutting knives are set at an angle φ (the larger this angle, the lower the cutting force). With an increase in this angle, forces are created that push the sheet out from under the knives, in connection with this, the value of the angle φ is selected in the range of 7. 12 °, which creates optimal conditions for cutting. The taper angle β is selected depending on the material to be processed (the harder the material, the larger this angle should be). For soft metals and alloys (for example, copper, brass), it is 65 °; for metals of medium hardness. 70. 75 °, and for solid materials. 80 °. If it is required to cut sheets of large thickness (up to 2.0 mm), use chair scissors (Figure 6). These scissors have one handle with a downward-bent end; with this pointed end, the scissors are fixed in a wooden block or vise. The second handle is used for pressing and actually cutting.

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α is the back angle; β is the angle of sharpening; φ. the angle between the blades

Figure 5. Geometric parameters of the scissors blades

A good effect when cutting sheet steel up to 2.5 mm thick can be achieved by using power scissors (Figure 7). When working, the handle four with a notch is fixed in a vice, and the handle five with a plastic tip is gripped with the right hand. Working handle five is a system of two levers connected in series. The first lever 7 ends with a knife one and connected with a screw 2 through a washer eight with handle four. Lever five through the axis 6 and pivot link 3 also connected to the handle four. This lever system provides approximately 2x the cutting force compared to conventional shears of the same size.

Tabletop manual lever scissors (Figure 8) is used for cutting sheet steel up to 4 mm thick, aluminum and brass. up to 6 mm. Base one scissors are bolted to the workbench. Handle 2 provides a reciprocating movement of the knife 3. Second knife four fixed in the base case one. The sheet to be cut is placed on the fixed knife shelf and moving the movable knife 3 handle 2, cut the sheet along the marking risk. Lever scissors may differ slightly from each other in design, but the principle of their operation is the same in all cases.

knife; 2. screw; 3. hinge link; 4. knurled handle; 5. handle with a plastic tip; 6. axis; 7. lever; 8. washer

Figure 8. Desktop manual lever scissors

Pipe cutters (Figure 9) is used for cutting pipes of various diameters instead of a hacksaw, as well as for better cutting pipes. The pipe cutter is a special device in which steel disk cutters-rollers serve as the cutting tool. The most common pipe cutters are roller, clamp and chain cutters.

Roller pipe cutter (Figure 9, but) consists of a staple four, screw lever 3 and three disc cutting rollers 6, two of which are mounted on axles in a bracket four, and the third is mounted on an axis fixed in a movable bracket 5

a. roller: 1. clamp; 2. screw; 3. screw lever; 4. bracket; 5. bracket; 6. cutting edges; 7. pipe; b. clamp; в. chain; g. incisal: 1. pressure screw; 2. cutting tool; 3. screw

The pipe to be cut is fixed in a clamp one screw 2, after which the pipe cutter is installed on the pipe 7. When rotating the screw lever 3 to the right, the bracket 5 will move the cutter wheel 6 until it touches the pipe wall under some pressure. A pipe cutter with three rollers cuts in three places at the same time, therefore, when working, it is slightly swayed with a lever (about one third of a turn in each direction). To improve the quality of cutting, the cutting site is lubricated with oil.

For cutting large diameter pipes, use clamp or chain cutters (Figure 9, b, c).

When cutting with roller pipe cutters, its end is pressed into the pipe, which leads to the formation of burrs and the need for further processing of the pipe to remove them. This drawback can be eliminated incisor pipe cutter (Figure 9, d), in which the rollers perform only the function of centering the pipe in the device, and cutting is performed with a cut-off cutter 2, which, as it plunges into the pipe, is fed by a pressure screw 7. The rollers are pressed using a screw 3.

Scissors

It is relatively easy to cut a smooth sheet with scissors, but with long cuts, you have to find ways to install the material so as not to damage your hands or workpieces. Complex configurations are difficult to produce, it is easier to follow a straight mowing line. When using an angle grinder with cutting discs, the edge burns, leaving unprotected metal on it.

Cutting a profiled sheet is much more difficult. The scissor blades lack a grip angle, so craftsmen are forced to find ways to grip and cut metal.

Ideas to adapt the existing tool to perform complex tinsmithing work have arisen for a long time. But not everyone is ready to purchase complex and expensive devices. Easier to use attachments with existing power tools.

How to make a roller shears for cutting sheet metal with your own hands

Cutting metal is one of the most popular and widespread methods of processing such material. In this case, it is mandatory to use special tools that provide the ability to cut sheet metal, since it is unrealistic to do this without using additional devices.

Cutting technology consists in the fact that the cutting edge of the tool acts on a workpiece made of a particular material. The sharp cutting edge of the tool moves along the surface of the metal, cutting it. During this process, the cut layer undergoes plastic deformation.

The main methods of cutting metal

Before buying, you need to figure out what methods of cutting metal exist. Specialists divide several groups:

All of them differ in execution technique, have certain advantages and disadvantages. As for the tools themselves for cutting metal, the most popular are:

  • a hand saw is known as a hacksaw blade;
  • electric jigsaw;
  • scissors for metal;
  • circular and saber saws;
  • angle grinder.

Each device has significant differences, they need to be selected depending on the goal.

Sheet metal cutting machines

At enterprises for the manufacture of metal products, a variety of tools are used to cut parts from sheet materials.

  • The guillotine shear is a wide-cutting machine in which sheet blanks are cut along a straight line of the mowing line. Machine drives: electric, hydraulic and pneumatic. Industrial equipment cuts steel sheets up to 6 mm thick.

When cutting a strip (rolled sheet material), rollers are installed from which the strip is wound. Additionally equipped with roller measuring devices, allowing high-performance cutting.

  • Hand guillotines are more common in small workshops. They can cut sheet blanks up to 2 mm thick. The cutting length is relatively short. If necessary, separation over a long length is cut in parts, gradually advancing the workpiece along the cutting edges. To make it easier for the operator to perform the work, tables are installed around the machine, on the surface of which roller tables are installed. It is easy to move semi-finished products along them.
  • Circular saws equipped with metal discs are used to make long cuts in sheets with a thickness of more than 2 mm. The process speed is low. To reduce the load on the tool, they are cooled using cooling lubricants (coolant).
  • The jigsaw is used to cut workpieces with a thickness of more than 1.5 mm. With a smaller thickness, the process is accompanied by strong vibration. Quality drops noticeably.
  • Jig-punching presses are used in fairly large industries. On them, according to a given program, complex parts are manufactured from sheet materials. The shape of the cut line can be very diverse. Holes of various shapes are made in the blanks. Modern machines perform over 5000 strokes per minute, which guarantees high productivity of punching parts.

Homemade roller knives

In such a case, a more correct solution would be to try to make such a tool with your own hands.

There can be a lot of roller knife designs, so making your own knife will not be difficult. But the main part of the tool. cutting knives. must be made of the highest quality and strongest alloy, the strength of which exceeds the material being cut. Otherwise, the quality of the trimmed edge will be very low and additional processing will be required.

Usually, even in factory models of roller knives, the resource is within 25 km of sheet metal 0.5 mm thick. If you cut sheet metal with a greater thickness, then the resource of use of the tool will decrease. But after that the rollers can be sharpened, with the result that the tool will be ready for work again.

As for the resource of using homemade roller knives, it directly depends on the quality of the material from which the cutting parts of the machine are made.

Tools and devices used for cutting

Methodical instructions for laboratory studies in the discipline “Fundamentals of repair and diagnostics of oil and gas equipment”

The instructions describe the tools and devices used in cutting, the basic rules for performing work when cutting metal, as well as the rules for cutting metals for students of specialty 130602 Machinery and equipment of oil and gas fields are given.

Compiled by: Sidorkin D.I., Assistant, Candidate of Engineering Sciences

Reviewer Ishemguzhin I.E., Associate Professor, Candidate of Engineering Sciences

© Ufa State Petroleum Technical University, 2007

3 Tools and devices used for cutting

4 Rules for performing work when cutting materials

The purpose of this laboratory work is to consolidate and deepen the practical knowledge of students on the tools used in cutting metal and methods of performing these works.

Cutting is an operation involving the separation of materials into parts using a hacksaw blade, scissors and other cutting tools. Depending on the tool used, cutting can be carried out with or without chip removal.

Tools and devices used for cutting

The most widespread is the cutting of metals with hand-held metal saws and scissors. Hand lever and guillotine shears are used to cut sheet and bar material.

Hand-held locksaw hacksaws are intended mainly for cutting section and profile rolled metal by hand, as well as for cutting thick sheets and strips, cutting grooves and slots in screw heads, cutting workpieces along the contour and other works, cutting is performed using hacksaw blades, which are made of carbon (grade P9 or P18) or alloyed (grade X6VF) tool steel and hardened after cutting the teeth. The most common hacksaw blades are 13 and 16 mm wide with a thickness of 0.5 to 0.8 mm and a length of 250.300 mm. To carry out cutting, the blade is installed in a special hacksaw machine. Hacksaw machines are of two types: solid and sliding, allowing you to install a hacksaw blade of different lengths in the machine.

One-piece hacksaw (Figure 1) consists of a machine 7, a tension screw with a wing nut 6 and a handle 2. The hacksaw blade 4 is installed in the slots of the heads 5 and fixed with pins 3.

machine; 2. handle; 3. pins; 4. hacksaw blade; 5. head of attachment of the hacksaw blade; 6. tension screw with nut

Testing Metal Cutting Tools | What works best?

The sliding hacksaw machine (Figure 2) differs in that it consists of two parts, connected by a clip. The holder is rigidly attached to one half of the machine, and the other half can change its position along the length by installing a pin pressed into it, which is fixed in special grooves of the holder.

Figure 2. Sliding hacksaw

On one side of the hacksaw blade, teeth are cut along the entire length (Figure 3, a). Each tooth of a hacksaw blade is given the shape of a cutting wedge, which is characterized by certain geometric parameters: clearance angle α, taper angle β, rake angle γ and cutting angle δ. There are dependencies between the angles characterizing the geometry of the cutting wedge of the hacksaw blade teeth: α β β = 90 °; α β = δ.

a. geometric parameters of the hacksaw blade: γ. rake angle; α is the back angle; β is the angle of sharpening; δ. cutting angle; b. wiring on the tooth; c. wiring along the canvas

Since the work (movement) of the hacksaw blade is carried out in a limited space, to prevent it from jamming during operation, the teeth of the hacksaw blade must be divorced. Depending on the size of the pitch of the teeth, that is, on the distance between two adjacent teeth, a tooth setting (Figure 3, b) and a setting along the blade (Figure 3, c) are distinguished. The spreading along the tooth is made on the canvases with a large step, in this case, each tooth of the hacksaw blade is alternately bent one way or the other. When spreading along the canvas, first bend two or three teeth in one direction, and then two or three teeth in the other. In this case, a wavy line appears along the canvas.

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When installing the blades in a hacksaw machine, you must ensure that the correct direction of the tooth is selected. The edge of the cutting wedge must always be directed towards the working movement of the blade. forward, in the direction from the handle to the thumbscrew of the tensioning screw. The second prerequisite for normal operation when cutting is the tension of the hacksaw blade. The tension should be such that the blade does not undergo elastic deformations during cutting and at the same time should not be too strong, as this can lead to breakage of the blade during operation, even if it is slightly skewed.

Manual scissors (Figure 4) are available as right and left. On the right shears, the bevel on the cutting part on each of the halves is on the right side, and on the left, on the left. Manual scissors can cut sheet steel up to 0.7 mm thick, roofing iron up to 1.0 mm thick, copper and brass sheets up to 1.5 mm thick.

a. right; b. with curved blades; c. finger

Such scissors (Figure 4, a) are designed to cut material along a straight mowing line or along an arc of a large radius. If you want to cut a hole in the sheet material or cut a part along a contour with small radii of curvature, use scissors with curved blades (Figure 4, b) or finger scissors with thin and narrow cutting blades (Figure 4, c).

All scissors, regardless of their design, are based (like other cutting tools) a cutting wedge. The shape of the scissors cutting wedge is characterized by the following geometrical parameters (Figure 5): angle of taper β; back angle α, providing a decrease in friction when working with scissors and constituting 2.3 °. In order to reduce the forces applied during cutting, the cutting knives are set at an angle φ (the larger this angle, the lower the cutting force). With an increase in this angle, forces are created that push the sheet out from under the knives, in connection with this, the value of the angle φ is selected in the range of 7. 12 °, which creates optimal conditions for cutting. The taper angle β is selected depending on the material to be processed (the harder the material, the larger this angle should be). For soft metals and alloys (for example, copper, brass), it is 65 °; for metals of medium hardness. 70. 75 °, and for hard materials. 80 °. If it is required to cut sheets of large thickness (up to 2.0 mm), use chair scissors (Figure 6). These scissors have one handle with a downward-bent end; with this pointed end, the scissors are fixed in a wooden block or vise. The second handle is used for pressing and actually cutting.

α is the back angle; β is the angle of sharpening; φ. the angle between the blades

Figure 5. Geometric parameters of the scissors blades

A good effect when cutting sheet steel up to 2.5 mm thick can be achieved using power shears (Figure 7). During operation, the handle 4 with a notch is fixed in a vice, and the handle 5 with a plastic tip is grasped with the right hand. Working handle 5 is a system of two levers connected in series. The first lever 7 ends with a knife 1 and is connected by a screw 2 through a washer 8 to the handle 4. The handle 5 is also connected to the handle 4 through the axle 6 and the articulated link 3. This system of levers provides an increase in the cutting force approximately twice as compared to conventional scissors of the same dimensions.

Tabletop manual lever scissors (Figure 8) are used to cut sheet steel up to 4 mm thick, aluminum and brass up to 6 mm thick. The base 1 of the scissors is bolted to the workbench. The handle 2 provides a reciprocating movement of the knife 3. The second knife 4 is fixed in the base body 1. The sheet to be cut is placed on the shelf of the fixed knife and, moving the movable knife 3 with the handle 2, the sheet is cut along the marking risk. Lever scissors may differ slightly from each other in design, but the principle of their operation is the same in all cases.

knife; 2. screw; 3. hinge link; 4. knurled handle; 5. handle with a plastic tip; 6. axis; 7. lever; 8. washer

Figure 8. Desktop manual lever scissors

Pipe cutters (Figure 9) are used for cutting pipes of various diameters instead of a hacksaw, as well as for better cutting pipes. The pipe cutter is a special device in which steel disk cutters-rollers serve as the cutting tool. The most common pipe cutters are roller, clamp and chain cutters.

The roller pipe cutter (Figure 9, a) consists of a bracket 4, a screw lever 3 and three disc cutting rollers 6, two of which are mounted on the axles in the bracket 4, and the third is mounted on an axis fixed in a movable bracket 5

a. roller: 1. clamp; 2. screw; 3. screw lever; 4. bracket; 5. bracket; 6. cutting edges; 7. pipe; b. clamp; в. chain; g. incisal: 1. pressure screw; 2. cutting tool; 3. screw

The pipe to be cut is fixed in the clamp 1 with the screw 2, after which the pipe cutter is installed on the pipe 7. When the screw lever 3 is rotated to the right, the bracket 5 will move the cutting roller 6 until it touches the pipe wall under some pressure. A pipe cutter with three rollers cuts in three places at the same time, therefore, when working, it is slightly swayed with a lever (about one third of a turn in each direction). To improve the quality of cutting, the cutting site is lubricated with oil.

To cut pipes of large diameter, clamp or chain pipe cutters are used (Figure 9, b, c).

When cutting with roller pipe cutters, its end is pressed into the pipe, which leads to the formation of burrs and the need for further processing of the pipe to remove them. This drawback can be eliminated by an incisal pipe cutter (Figure 9, d), in which the rollers perform only the function of centering the pipe in the device, and cutting is performed with a cutting cutter 2, which, as it plunges into the pipe, is fed by a pressure screw 7. The rollers are pressed using a screw 3.

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Roller knives for metal

Roller knives are used very often in the modern metalworking industry to cut sheet metal. The work of such a tool consists in the work of its two main elements. cutting discs. Rotating in different directions, these rollers-discs are pressed into the material, carrying out its cutting. Due to friction between metal and knives, the workpiece moves along the tool.

Most often, there are roller knives for metal, which consist of two rollers. In such a tool there are two rotating discs. the lower and the upper. Now there are such tools of three types of knives:

  • with a parallel position;
  • with one inclined;
  • with several inclined.

The first group of such cutting tools is mainly intended for cutting material into strips.

The second group is designed for cutting metal into strips, as well as for round and circular blanks.

The third group is mainly used for cutting ring, round and curved workpieces with a small radius.

All of these knives are well suited for cutting sheet metal quickly. At the same time, the cut edge of the material does not need any additional processing.

Metal cutting. Tools and fixtures

Cutting is an operation involving the separation of materials into parts using a hacksaw blade, scissors and other cutting tools. Depending on the tool used, cutting can be carried out with or without chip removal.

Tools and devices used for cutting

The most widespread is the cutting of metals with hand-held metal saws and scissors. Hand lever and guillotine shears are used to cut sheet and bar material.

Hand-held locksaw hacksaws are intended mainly for cutting sectional and profiled rolled stock by hand, as well as for cutting thick sheets and strips, cutting grooves and slots in screw heads, cutting workpieces along the contour and other works. Cutting is performed using hacksaw blades, which are made of carbon (grade P9 or P18) or alloyed (grade X6VF) tool steel and hardened after cutting the teeth. The most common hacksaw blades are 13 and 16 mm wide with a thickness of 0.5 to 0.8 mm and a length of 250 300 mm. To carry out cutting, the blade is installed in a special hacksaw machine. Hacksaw machines are of two types: solid and sliding, allowing you to install a hacksaw blade of different lengths in the machine.

A one-piece hacksaw (Fig. 2.53) consists of a machine 1, a tension screw with a wing nut 6 and a handle 2. A hacksaw blade 4 is installed in the slots of the heads 5 and fixed with pins 3.

The sliding hacksaw machine (Fig. 2.54) differs in that it consists of two parts, connected with a clip. The holder is rigidly attached to one half of the machine, and the other half can change its position along the length by installing a pin pressed into it, which is fixed in special grooves of the holder.

On one side of the hacksaw blade, teeth are cut along the entire length (Fig. 2.55, a). Each tooth of a hacksaw blade is given the shape of a cutting wedge, which is characterized by certain geometric parameters: a back angle a, a taper angle (3, a front angle y and a cutting angle b.

Since the work (movement) of the hacksaw blade is carried out in a limited space, to prevent it from jamming during operation, the teeth of the hacksaw blade must be divorced. Depending on the size of the Tooth pitch, that is, on the distance between two adjacent teeth, a tooth setting is distinguished (Figure 2.55, b) and a blade setting (Figure 2.55, c). The spreading along the tooth is made on the canvases with a large step, in this case, each tooth of the hacksaw blade is alternately bent one way or the other. When spreading along the canvas, first bend two or three teeth in one direction, and then two or three teeth in the other. In this case, a wavy line appears along the canvas.

When installing the blades in a hacksaw machine, you must ensure the correct choice of the direction of the tooth. The edge of the cutting wedge must always be directed in the direction of the working movement of the blade. forward, in the direction from the handle to the thumbscrew of the tensioning screw. The second prerequisite for normal cutting operation is the tension of the hacksaw blade. The tension should be such that the blade does not undergo elastic deformations during cutting and at the same time should not be too strong, as this can lead to breakage of the blade during operation, even if it is slightly skewed.

Manual scissors (fig. 2.56) are right and left. On the right scissors, the bevel on the cutting part on each of the halves is on the right side, and on the left ones. on the left. Manual scissors can cut sheet steel up to 0.7 mm thick, roofing iron up to 1.0 mm thick, copper and brass sheets up to 1.5 mm thick.

Such scissors (Fig. 2.56, a) are designed to cut material along a straight mowing line or along an arc of a large radius. If you want to cut a hole in the sheet material or cut a part along a contour with small radii of curvature, use scissors with curved blades (Figure 2.56, b) or finger scissors with thin and narrow cutting blades (Figure 2.56, c).