Metal cutting metal cutting metal bending
Metal cutting: application
The main purpose of the operation is to divide the workpiece into several parts in predetermined proportions. To do this, markings must be applied before processing and the optimal method is selected. Cutting can be carried out both along the length and along the width of the workpiece. Thanks to this, it is possible to significantly reduce the number of operations, which means to reduce the total cost of the finished part.
Various metal cutting technologies are usually used to solve the following tasks:
- Removing the top layer and defects on the surface of the workpieces.
- Removing edges after casting or stamping.
- Dividing the workpiece into separate parts.
- Creation of grooves, grooves and so on.
- Punching holes.
All the tasks described above are found in various fields of industry, from construction to the creation of complex machines and other equipment. They are used both in small workshops and in large enterprises.
One of the disadvantages of cutting metal is the need for subsequent processing of the edges. Since they can turn out to be torn, they are sanded to correct defects.
Methods and technologies for cutting metal
There are several types of classification based on different criteria. The most common are the following:
- By the nature of the tasks. We have listed them in the previous paragraph. There are also atypical problems for which other methods are applied.
- By the level of automation: manual and mechanized processing.
- By the fixation method. It can be a vice or steel substrates, as well as special devices in the construction of machine tools.
- In the direction of the deckhouse. It can be horizontal or vertical. The choice depends on the possibilities of clamping the workpiece.
The choice of the best approach depends on various factors, including:
- the availability of the necessary tools and / or equipment;
- features of the workpiece: type of metal / alloy, thickness, shape, and so on;
- requirements for the quality of the part. If a high level of precision is required, machining is usually applied;
- volume of production. For the serial production of parts, automated CNC machines are usually used. If we are talking about the processing of single workpieces, it is irrational to reconfigure production. In these cases, manual processing is usually used.
Appointment, rules and techniques for cutting metal
Metal cutting is one of the basic types of metal processing. It is, perhaps, only historians who will be able to say exactly when it first began to be applied. It is also used today, but progress has helped make it much simpler, more accurate, and more efficient. In today’s article we will talk about the purpose, rules and techniques of cutting metal. We will tell you about various technologies, what methods were used before and what methods are used today.
First of all, it is necessary to determine what the methods of cutting metal are, as well as their purpose. It is easy to understand that in itself this process involves the division of an object into several parts. The same is true for metal. This method is quite versatile and can be applied to almost all types of blanks, from sheets and rods to pipes and large rolled products. Of course, to solve these problems, you will need different equipment.
All types of felling techniques have a basic similarity. they involve processing with a percussion or hydraulic tool that breaks through the metal. This is the main difference between the technology and cutting, in which the main type of impact is pressure.
Subject to a number of rules for cutting metal, the simplest operations can be performed at home. complex work is usually carried out in the workshop, and in large factories, various methods are used for mass production of products.
Before moving on to the next section, it is necessary to identify one more point, namely the relationship between cutting and chopping. Many metalworking companies do not share these methods for their clients. This approach gives you more freedom in choosing the optimal processing method.
At the same time, cutting and chopping metal have many differences, the main of which is the method of influence and the tools used. Most locksmiths, not to mention large enterprises, use both technologies, depending on what result you want to get.
Semi-automatic and automatic processing
The principle of operation in this case is much simpler: a person makes the markings and fixes the workpiece on the machine. All work related to the application of effort is performed by the machine. Depending on the type of equipment installed in production, the felling procedure can be performed in a semi-automatic or fully automatic mode. In the latter case, the machine independently selects most of the parameters.
The main advantages of this approach are high performance and level of accuracy. The disadvantages include only the high cost of the necessary equipment: only large companies can buy and maintain machines.
The main type of mechanical cutting of metal, as a rule, is considered to be guillotine, that is, produced on a guillotine machine. Modern devices have little in common with the weapon used for execution several centuries ago, with the exception of the principle of operation. The guillotine machine assumes the presence of an oblique blade, which moves in one plane without changing the angle of inclination. Such devices cannot be called new: the first samples are, perhaps, the same age as the tools that gave them the name. Modern machines, however, are much more advanced and can work in both semi-automatic and automatic modes.
Why is the technology, invented several centuries ago, used today in a wide variety of industries? The fact is that the guillotine felling has a number of undeniable advantages, which become even more evident with the use of modern technologies. These include high quality work and simplicity.
The main elements of the guillotine machine are:
- table for placing blanks. In some machines it is stationary, while in others it may have moving elements;
- stop-lock, which reliably fixes the workpiece and ensures safety during work;
- movable upper beam with a blade. It is this part of the machine that is responsible for the felling;
- bottom blade. It is not available on all machine models. It improves the quality and accuracy of cutting and can be used for cutting. The bottom blade is usually static;
- presses and clamps. They provide fixation of various types of workpieces in a given position.
It is also important to take into account the fact that today there are machines on the market with different types of drives: manual, hydraulic, pneumatic and so on.
The operating procedure for this device is quite simple:
- The workpiece is placed on the work table and fixed in a predetermined position.
- After that, one or two blades are exposed to the metal (depending on the type of machine).
When using serviceable equipment, very little scrap steel is generated. In addition, subject to proper operation, the edge remaining after cutting does not require subsequent processing, which also allows to reduce the cost and speed up production.
There are other types of metal shearing machines, but they are generally less used:
- scissor presses;
- corner nibbling machines.
Manual cutting of metal
This type of processing is less productive, therefore it is more often used to create single parts. In addition, hand chopping tools, despite their great variety, cannot provide the level of precision that CNC machines guarantee.
Before starting machining, the wizard must choose the direction of the tool movement. horizontally or vertically. It all depends on how you can fix the workpiece. The most common fixing option is a vise. They prevent slipping and ensure a secure hold of the workpiece. Their main disadvantage is the limitations on the shape and thickness of the parts. Large workpieces are usually processed on a special table, on which a steel plate is mounted for strength. Self-tapping screws and rubberized pads are used for a more reliable fixation.
The next step is the choice of tools. Usually, a hammer is used to carry out manual processing, as well as a cross-cutter or chisel. As already mentioned, these tools allow you to work with the most common types of workpieces from most metals.
The required level of quality and accuracy is provided by the skills of the master. We have already mentioned that the felling process involves breaking through metal in a given area. A crosscutter or chisel provides a point application of force, but the master does the main work with a hammer. Of course, one of the key factors in this case is the force of the impact. In this case, more does not always mean better. Experienced craftsmen first make a notch on the metal in order to subsequently avoid the blade sliding off. If the master cannot correctly apply efforts, he risks ruining both the workpiece and the working tool. Experienced locksmiths, on the other hand, can provide a level of precision comparable to that guaranteed by machine tools.
Another important point in the skill of a locksmith concerns working with a hammer. This tool, despite its simplicity, is responsible for the competent application of power and ensures the required quality of work. The main movement that a specialist makes is a blow. However, the work of a locksmith is much more complex than solving everyday tasks like hammering nails. Even a stroke in plumbing has many nuances. There are three types of them in total:
In order not to go into details, we present an image from a textbook published in the USSR:
The force of the blow depends on where the swing begins, as well as on the length of the hammer handle. Knowledge of this technique gives the craftsman the ability to apply as much effort as is required to create chisels or to break through metal.
Manual cutting of metal does not involve a large number of operations. It is necessary to securely fix the workpiece using the available tools, mark it out, and then strike with a hammer and chisel. An experienced craftsman can easily control the position and tilt of the instruments, as well as the applied force.
The main advantages of manual metal cutting is the relatively low cost of such work. one employee and buying a tool is within the power of even small companies. Some felling tasks can be done even at home.
The disadvantages of this method include:
- Sufficiently low performance. Even an experienced craftsman will not be able to achieve the speed comparable to a modern machine tool. As a result, manual processing is used for single parts or in small industries.
- Labor intensity. Manual machining cannot be used for large or irregular workpieces. In addition, it requires the application of force from the master, which significantly increases the time required for felling.
- Low accuracy of work. Even the highest quality tools will not deliver a level comparable to CNC machines.
- Low quality of the log house. It must be processed: grind and so on. As a result, the time required for the release of each part increases.
Metal chopping is a process that involves breaking through a workpiece at predetermined locations. It is used in various industries and is often used at home. Cutting can be carried out in different ways: in manual, semi-automatic or automatic mode. In each case, a specific tool and equipment is used.
Exploring Sheet Metal Bending
Metal cutting metal cutting metal bending
Straightening is a locksmith operation designed to eliminate distortions in the shape of a workpiece (dents, bulging, waviness, warping, curvature, etc.) by plastic deformation. The metal is straightened both in the cold and in the hot state. Straightening can be done manually on a steel or cast iron plate or on an anvil. Machine straightening is performed on presses and straightening rollers.
For straightening, use: hammers made of soft materials (copper, lead, wood) with a round polished striker (square striker leaves traces in the form of nicks); trowels and supports (metal or wooden bars) for straightening thin sheet and strip metal; correct headstock for hardened parts with shaped surfaces.
The curvature of the workpieces is checked by eye by the gap between the plate and the workpiece laid on it. Curved places are marked with chalk. The simplest is to edit flat metal. In this case, with a hammer or a sledgehammer, strong blows are applied to the most convex places, reducing the force of the blow as they straighten. In this case, the workpiece is periodically turned from one side to the other. difficult is the straightening of metal curved along the edge. Here they resort to stretching a part of the workpiece. It is recommended to straighten metal with a twisted (spiral) bend using the untwisting method. To do this, one end of the workpiece is clamped with a bench vise, and the other with hand vise. Then the curvature is straightened with a lever. The results of the straightening are checked by eye, and a more accurate check is carried out on a marking or control plate along the lumen.
Editing sheet material is a complex operation.
It depends on the type of deformation of the workpiece (bulges or dents in the middle of the sheet, waviness of the edges and edges, simultaneously bulges and waviness of the edges, etc.). On the workpiece, wavy areas are preliminarily outlined with chalk or pencil, then it is placed on the slab with the bulge up so that the workpiece lies with its entire surface on the slab. Holding the sheet with the left hand in a mitten, with the right one strikes with a hammer from the edge of the sheet towards the bulge (as shown by arrows at 2.5, a). As you get closer to the bulge, the blows should be weaker and more frequent. During straightening, the sheet is turned in a horizontal plane so that the blows are evenly distributed around the entire area of the workpiece. In the presence of several bulges, blows are applied in the interval between them, as a result of which the sheet is stretched and all “bulges are brought together into one, which is straightened in the above way. If the sheet has waviness at the edges, but an even middle, then the blows are applied from the middle of the sheet to the edges As a result, the sheet in the middle is stretched and the waves along its edges disappear. After that, the sheet is turned over and continues to be straightened in the same way until the required tolerances of straightness and flatness are obtained. To straighten thin sheets, use wooden mallet hammers, and very thin sheets are ironed with wooden or metal In this case, the sheets are periodically turned over. The quality of straightening is controlled using a ruler.
Straightening (hardened workpieces are carried out with various hammers with a hardened striker or a special hammer with a rounded narrow side of the striker. The blows are applied not on the convex, but on the concave side of the workpiece. In this case, the metal fibers on the concave side are stretched and the workpiece is straightened in which, after quenching, the angle between the measuring sides has changed, is produced in the following ways: if the angle is less than 90 °, then hammer blows are applied at the top of the inner corner, if more than 90 °, at the top of the outer corner.
Bending is one of the most common locksmith operations. It is used to give the workpiece a curved shape along a given contour. In the process
bending, the metal is subjected to the simultaneous action of tensile and compressive stresses, therefore, here it is necessary to take into account the mechanical properties of the metal, its elasticity / degree of deformation, thickness, shape and dimensions of the section of the workpiece, angles and bending radii of the part. The bending radius of the part should not be taken close to the minimum permissible, unless it is dictated by design requirements. It is advisable not to allow the bending radius less than the thickness of the workpiece, as this leads to the appearance of cracks and other defects. In the cold state, it is recommended to bend parts from sheet steel up to 5 mm thick, from strip steel up to 7 mm thick, from round steel up to 10 mm in diameter.
When bending a strip of sheet steel, a bend is first applied to it. Then the workpiece is clamped in a vice between the squares-mouthcups so that the marking of the risk faces the fixed jaw of the vice and protrudes 0.5 mm above it. Finally, bend the end of the strip with hammer blows directed towards the stationary jaw.
To bend the staples, the workpiece is clamped in a vice between the square and the mandrel bar and the first end is bent. Then, putting a mandrel bar of the required size inside the staple, the staple is clamped in a vice at the level of the notches and the second leg is bent.
Bending of a strip at an acute angle using a special mandrel is shown in 2.7, d.
The bending of a clamp made of thin strip steel is performed in the following sequence: first, a mandrel of the required diameter is clamped in a vice. Then the workpiece is bent on the mandrel with two pliers and the clamp is finally processed with a hammer on the mandrel in a vice. Lapping the half-open clamp is performed on the plate.
In machine designs, there are nodes with different directions and forms of bending of parts: a cotter pin or washer in a nut-bolt connection; bending of both parts to be joined; one of the parts of the assembly is bent into a recess or hole in the other.
Bending work is also carried out in connection with the fitting of various pipes. In the cold state, copper and brass tubes of small diameter (up to 8
mm) for large radii of curvature (more than 10.12 diameters). The same larger diameter tubes (8.14 mm) are bent by hand using templates or tightly wound spiral springs that are placed inside the tube at the bend. Pipes with a diameter of more than 20 mm are bent, as a rule, with the help of special devices or on bending machines, after filling the pipes with sand or molten rosin. Copper and brass pipes are annealed in the bend zone before bending. Steel pipes with a diameter of up to 10 mm are bent without heating and without filler, while pipes of large diameters are bent hot and, as a rule, with a filler. Hot bent aluminum and duralumin pipes. Pipes are heated only in the bend zone for
a length of approximately jgd, where a is the outer bending angle;
Cutting is an operation of metal cutting. With the help of a cutting tool. a chisel, a cross cutter or a grooving tool. an excess metal layer is removed from the workpiece, it is cut into pieces, a hole is cut, lubrication grooves are cut, etc. high processing precision is required. Cutting of small workpieces is performed in a vice, large workpieces are cut on a slab or anvil.
The following tools are used for cutting: chisels, crosscutters, flutes.
The locksmith chisel consists of three parts: working 2, middle 3 and impact (striker) 4 (2.10, a). The wedge-shaped cutting edge of the chisel 1 and the firing pin are hardened and released. After heat treatment, the hardness of the cutting edge reaches HRC356. 61, striker. HRC337. 41. The chisel has a length of 100.200 mm, and the width of the cutting edge, respectively, 5. 25 mm. The angle of sharpening of the chisel, depending on the material to be processed, should be:
Hard materials (cast iron, hard steel, bronze) 70 °
Medium hard materials (steel) I. 60 °
The smaller the taper angle, the less force must be applied to cut. However, the greater the hardness and brittleness of the metal being processed, the stronger the cutting edge should be and the greater the taper angle; The chisel striker has the form of a truncated cone with a semicircular upper base. Therefore, the blow struck by the hammer always falls on its center.
The crosscutter differs from the chisel by a narrower cutting edge (2.10, b). It is used for cutting narrow grooves, grooves, etc. The sharpening angles, the hardness of the working and striking parts of the cross cutter are the same as those of the chisel.
Kinavochniki (2.10, c) differ from the cross-cutter in the curved shape of the cutting edge and are used to cut out lubricating grooves in the bearing bushings and bushings and in other similar works.
Before work, the chisel is placed on the workbench on the left side of the vise with the cutting edge towards itself, and the hammer on the right side of the vise with a striker directed towards the vise. The correct position of the locksmith’s body is of great importance during felling: the vice must be firmly half-turned to them.
The quality and productivity of the felling depends on the hammer blow. There are three types of hammer blows: wrist, elbow and shoulder. With a wrist blow, only the right hand is bent. Such a blow is used when performing light and precise work: removing thin layers of metal, removing small irregularities, cutting thin sheet steel, etc. With an elbow blow, the hand bends at the elbow and the blow is stronger. This blow is used when removing a layer of metal of medium thickness, cutting grooves and grooves. With a shoulder impact, the arm moves in the shoulder, while
it turns out a big swing and the maximum impact force. Shoulder impact is used when cutting thick metal, removing a large allowance in one pass, processing large planes. The frequency of hammer blows should be from 40 to 60 beats per minute with wrist and from 30 to 40. with elbow and shoulder blows. When cutting, the hammer is taken by the handle with the right hand on the strip and sheet metal at a position of 15.30 mm from its end so that four fingers cover the handle, and the thumb is placed on the index finger. The chisel is held with the left hand, without tightly squeezing the fingers, at a distance of 20.30 mm from its head. 26
To protect the hand from an accidental hammer blow, it is advisable to put a rubber washer with a thickness of 8.10 mm and a diameter of 45.50 mm on the upper part of the chisel.
When cutting metal, the correct setting of the chisel axis relative to the workpiece surface to be processed is of great importance. The angle between the workpiece (the planes of the vise jaws) and the chisel axis should be equal to 45 °, the angle of inclination of the chisel depends on the sharpening angle of the cutting edge and should be 30.35 °. At a lower angle of inclination, the chisel slides, rather than cuts, at a larger angle, it too deeply deepens into the metal, creating a large unevenness of the processed surface.
When chopping, the hands must act in concert. With your right hand, you should accurately hit the chisel with a hammer, and with your left hand, move the chisel over the metal. In this case, you need to look not at the head, but at the cutting edge of the chisel.
When cutting strip and sheet metal at the level of the vise jaws, the part of the workpiece that goes into the shavings (cut off) should be located above the jaws, and the marking risk should be exactly at their level without skewing.
Felling is performed with an elbow blow. When placing markings above the level of the jaws, the angle between the axis of the chisel and the surface to be processed is periodically reduced
When cutting a layer of metal on a wide flat surface, the marking marks should protrude 5.10 mm above the vise jaws. In this case, grooves with a width of 8.10 mm are first cut with a cross cutter. The width of the gaps between the grooves should be 0.8 of the length of the chisel cutting edge. Then the formed ledge is cut with a chisel. The thickness of the shavings removed by the cross cutter in one stroke is equal to 0.5. 1 mm, and when cutting down protrusions with a chisel. 1.5. 2 mm. Cast iron, bronze and other brittle metals are chopped without reaching the opposite edge of the workpiece. Unharvested places should be cut from the opposite side or beveled at an angle of 45 ° beforehand.
When cutting grooves and curved lubricating grooves (2.14.6), first, marks are applied to the workpiece surface to be machined, then grooves are cut with a cross cutter with a depth of 1.5. 2 mm for each pass. The unevenness remaining after cutting is eliminated with a groove, giving the grooves the same width and depth along the entire length of the workpiece.
When cutting a figured workpiece on a slab or anvil, the marked contour is first cut with light blows, departing from the marks by 2.3 mm. The sheet is chopped with strong blows on the chisel. If the sheet is sufficient
but thick, it is turned over and chopped from the opposite side along the designated contour. When punching out a workpiece with curved contours, you must use a chisel with a rounded blade or a cross cutter.
Various methods of cutting metal are shown in 2.15.
Metal cuttingchannel letter bending welding
Sharpening of chisels and crosscutters is carried out on sharpening (grinding) machines. For sharpening tools made of tool steels (carbon, alloyed from electrocorundum with a grain size of 40, 50 or 63 on a ceramic bond. screen and turn on the machine.The chisel is set at an angle of 30.40 ° to the periphery of the circle and with light pressure is slowly moved along the entire width of the circle.During work, it should be periodically turned one side or the other to ensure uniform and symmetrical sharpening. each time the chisel is immersed in water for cooling. The lateral edges of the chisel after sharpening should be flat, the same width and have the same angles of inclination. The angle of sharpening is checked with a template, which has angular notches of 70, 60, 45 and 35 ° (2.16, b). After sharpening with a fine-grained abrasive bar, deburr is removed (the blade is tucked in).
Cutting is the operation of dividing round, strip, profile rolled products, as well as pipes, manually and mechanically into parts. Manual cutting of workpieces, depending on the profile and cross-sectional area, is performed using various tools: hacksaws, scissors
(hand, chair, lever), pipe cutters and gas flame burners. It consists of a frame (hacksaw), a movable head, a screw with a nut for tensioning the hacksaw blade and a fixed head with a shank and a handle. Hacksaw frames are solid and sliding.
A hacksaw blade is a thin and narrow steel plate with teeth on one edge. Each tooth of a hacksaw blade has the shape of a wedge (cutter), on which the rear
angle a, taper angle 8, rake angle v and cutting angle b,
A hand saw is the most common tool for cutting thick sheets of strip and profile metal, as well as for cutting grooves,
To reduce the friction of the hacksaw blade against the walls of the metal being cut (cut), its teeth are spread in different directions, thus increasing the thickness of the blade h to the width of the cut. The teeth with a large pitch are bent one by one to the right and left, the teeth with a small pitch are bent two or three to the right and two or three to the left; this should form a wavy line.
When cutting metal with a hacksaw, the locksmith’s body should be turned to the right at an angle of 45 ° to the axis of the vice. The position of the legs is shown in 2.17, e.
Before you start cutting metal, you need to choose a hacksaw blade taking into account the hardness, shape and size of the metal being cut. The degree of tension of the blade in the hacksaw frame is checked by lightly pressing a finger on the blade from the side: if it does not bend, then the tension is considered sufficient. When working, the end of the handle should rest against the middle of the palm of the right hand, and the thumb should lie along the top of the handle. With the left hand, the hacksaw frame is taken so that the thumb is inside the frame, and the rest cover the tension screw of the movable head. The hacksaw is held in a horizontal position, moving smoothly, without jerking and producing from 30 to 60 double strokes per minute. During the course of the hacksaw, at least 2/3 of its length should work. When cutting with a hacksaw, thin material is clamped in a vice between two wooden blocks and cut with them. Metal cutting techniques are shown in 2.18.
As is known, the cut off metal layer in the form of chips can have a different appearance depending on the processing conditions.
Electric welding and gas cutting of metal. Cutting aluminum, cast iron. To increase the productivity of welding works, semiautomatic.
Electric welding and gas cutting of metal. Metal cutting. Fundamentals of metal cutting. Welding of non-ferrous metals and their alloys.
Electric welding and gas cutting of metal. Metal cutting. Fundamentals of metal cutting. Welding of non-ferrous metals and their alloys.
Mechanical cutting is usually used for metal with a thickness of up to 10-12 mm, and in some cases, up to 25-30 mm.
Electric welding and gas cutting of metal. Cutting aluminum, cast iron. To increase the productivity of welding works, semi-auto.
Electric welding and gas cutting of metal. Metal cutting. Fundamentals of metal cutting. Welding of non-ferrous metals and their alloys.
§ 8. Cutting metals. Depending on the shape and size of the material of workpieces or parts, cutting during manual processing of metal is carried out using manual or.
Cutting metal. simple and clear about all the nuances of the process
Cutting metal in modern plumbing is considered an auxiliary type of operations. It is carried out, if necessary, to remove the hardened crust from the metal surface, divide the workpiece into several parts, eliminate tides and various irregularities on castings and forgings.
Tools for cutting metal products and sheets
Cutting of metal is usually done with a sledgehammer, cross-cutter, metal hammer, blacksmith’s and metal chisel on a plate, in an ordinary vise, or on an anvil. It is also possible to cut a sheet of steel or nonferrous metal with a guillotine.
A chisel is a hard steel rod with a wedge-shaped cutting edge. If the cutting and cutting of metal, which is considered to be non-ferrous, is performed, the angle of sharpening of the chisel is from 35 to 45 degrees. But when processing steel sheets, the specified angle is chosen equal to 60 degrees.
A cross cutter is a narrow chisel that is used to produce narrow grooves and grooves. The working parts of a narrow and regular chisel must be hardened to a length of about 3 centimeters. It also requires hardening of the metal on the tool head (by about 1.5-2.5 centimeters) so that it cracks and does not paint when the chisel is hit with a hammer.
Plumbing most often involves the use of chisels with blades of 2 and 2.5 centimeters (the width of the working tool) with a total length of 20 and 17.5 centimeters. Crosscutters have a smaller blade width (no more than 10 cm) and a length of up to 17.5 cm. Note that the heads of chisels (regular and narrow) are usually cone-shaped, which:
- reduces the risk of mushroom-shaped caps forming on the head;
- facilitates the process of correctly hitting the tool with a hammer.
It is very important to ensure that the chisels do not have any serious defects on their surface (for example, trapping or deep cracks). Safety precautions categorically prohibit the use of such a tool for performing any options for metal processing (bending, chopping, cutting).
Chisels should be sharpened periodically so that they do not lose their cutting ability.
Sharpening is carried out with abrasive wheels of special sharpening machines. When performing this process, the chisel blade is cooled (using ordinary water). If the tool is not cooled, excessive heating of its working part will be observed, which in most cases leads to tempering, which will simply ruin the chisel. Working with it after unsuccessful hardening is prohibited by safety precautions.
Cutting of metal (as well as its bending) is carried out with bench hammers of standard weight (from 400 to 800 grams). Their oval handles are made of wood with high viscosity and hardness (mountain ash, maple, birch, oak). The length of the handles varies between 35-45 centimeters, they should not have cracks and knots that can injure the hands of the person processing (bending, cutting, chopping) metal products.
Separately, we will say that the ends of the handles of hammers for felling must be fixed with thin (1-3 millimeters) wedges made of steel or wood. After installation, wedges made of metal are closed, and wedges made of wood are fixed with special glue.
Devices for cutting metal billets
Depending on how, in the process of performing the operation, the working tool is positioned in relation to the product, two chopping options are distinguished. She may be:
The vertical process is carried out on an anvil or on a slab. With such cutting, products requiring processing are laid horizontally on the working surface, and the chisel is placed vertically in relation to them. Horizontal felling is carried out in a vice. In this case, the face (back) of the working tool is mounted to the jaws of the vice (to their plane) at a very small angle (almost completely horizontally).
Cutting of sheet metal is often done on a slab (on an anvil). In this case, the tool is put at risk (special markings applied to the workpiece), then one blow is carried out with a hammer. After that, the blade is mounted in such a way that half of it fits into the hole that we managed to make. Cutting the sheet according to this scheme, firstly, simplifies the process of installing the chisel in the desired position, and secondly, it guarantees a continuous cut.
In cases where sheet metal with a thickness of more than two millimeters is cut, the product is marked on both sides. In this case, the workpiece is processed first from one side, then it is turned over to the other side and cut completely. If the sheet thickness is less than two millimeters, it is recommended to put a piece of soft steel on its back side. This will prevent the working tool from becoming blunt when hitting the anvil.
Another point that should be taken into account when processing sheet products of complex configuration is that it is required to cut a small groove of shallow depth on them. The specified groove is made from the marking at a distance of about 1-2 millimeters. After that, you can chop the metal along the groove with full force until the contour to be cut shows itself on the back of the product. And then you will need to complete the operation by turning the workpiece over.
Bending and cutting of a sheet can also be done in a vice. In this case, the product is fixed so that, in relation to the sponges, the marking risk is located several millimeters lower. Cutting metal in a vice under such conditions allows you to leave a small allowance on the product, which is used for finishing the sheet edges (filing them). The cutting tool is tilted to the edges of the vise jaws at an angle of 45-60 degrees, to the cutting plane. at an angle of no more than 40 degrees.
Industrial bending and cutting of metal blanks
Many large enterprises use electric and pneumatic hammers, which greatly facilitate the metal processing process. Sheet blanks are often cut with a guillotine, on special dies and on presses. Plasma or laser cutting technology can be used to process high-strength steels. In addition, a machine for cutting reinforcement is often used (in fact, we are talking about the fact that the metal is chopped with a guillotine).
Industrial cutting and bending of metal sheets and products due to the aforementioned units greatly simplifies the metalworking operation, and also reduces the cost of work. It makes sense to use a guillotine or a press when products are made from metals of any non-standard shapes. Chippers are indispensable in the manufacture of embedded parts and steel strips.
Guillotine processing involves the use of knives and scissors for cutting metal. These tools do not wrinkle the edges of the workpieces, their cut is very accurate and truly accurate, which is rarely achieved with a hammer and chisel. Also, the cutting with a guillotine ensures the absence of on the metal:
- sickle-shaped deviations;
- uneven bevels;
- small notches.
over, the voiced flaws on the material do not appear even then, workpieces with a small thickness are processed.
Industrial presses (equipped with an electric motor, screw for manual operation) are usually used for cutting sewer pipes made of cast iron. Such mechanisms function quite simply. The locksmith assembles the rollers and press knives for the section of the pipes being processed, then places the pipe products on the rollers, making sure that the blade of the lower cutting tool matches the intended cut line.
After that, the engine starts, if we are talking about a machine with an electric drive, or manually lowers the upper knife onto the pipe. When the knives are compressed (from below and from above), an incision is formed on the workpiece (it is located on the sides of the pipe). Then the product is wedged and split. The design of the presses is such that one specialist can service such mechanisms.
Sheet metal cutting operations(punching & blanking)
In a way, this is a kind of cutting, but of a different character of execution. Also, the working tool in this case differs from the standard cutting. Chisels, grooving machines and crosscutters are used for cutting. For example, using a chisel, you can separate a layer of a metal surface, cut a workpiece in parts, make grooves or make a hole. However, the possibilities for the implementation of complex forms of harvesting by cutting are limited. In this sense, straightening and bending metals are more productive operations. Cutting is used in situations where, for various reasons, it is impossible to use machining and high requirements are not imposed on the workpiece in terms of the accuracy of the parameters. For example, if you need to remove excess weight for subsequent processing with files, the sharpening tool, if necessary, will correct the shape formed by the same chisel.
With the help of editing, the master changes the shape of the metal workpiece, restoring its previous appearance after damage. For example, the entire range of straightening works in auto repair shops can be attributed to the operations of straightening and bending metals, during which distortions, dents, swelling, warping and other defects are eliminated. Carrying out such work is possible both under the condition of thermal effect on the workpiece, and in its cold state. However, heating softens the metal, which gives the performer an advantage. As for the tool, hammers, anvils, pliers, mallets, hydraulic presses and clamping mechanisms are used in the manual format.
The mechanized method is realized using machine presses and straightening rollers. Separately, it is worth noting the straightening stand (slipway), which, due to great effort, allows the correction of massive structures. Also, manual straightening and bending of metal can be performed on the stocks. Tools in the form of a vice and clamping mechanisms make it possible to eliminate complex deformations when interacting with the complete equipment of the stand. Such complex operations are usually performed at the sites of the same auto repair shops.
One of the most common processing operations that allows you to divide a workpiece into separate parts. Cutting can be done both manually and mechanically. In the case of a manual approach, metal hacksaws, scissors, flame burners and pipe cutters can be used. But this tool is not capable of handling thick and high-strength workpieces. At the very least, the process will be laborious and will not allow you to get a high quality product. For this reason, straightening, bending, metal cutting and other locksmith operations are often performed on machine tools. In particular, turning models of equipment are used for cutting. The highest quality cutting is provided by plasma and waterjet machines. The direction of the sandblast stream on the material ensures high-precision cutting of thick workpieces, regardless of the grade of the alloy.
This operation allows you to give the product a curved shape in accordance with the specified contour. During the working procedure, the workpiece is subjected to compressive and tensile forces, which are provided by a special tool. In particular, bending is realized by means of a vice, pliers, presses and the aforementioned clamps. As you can see, the straightening and bending of metals are similar in that they involve the use of a whole group of tools in the work at the same time, some of which provide fixation of the workpiece. But in this case, there are also some nuances in terms of the bending technique. For example, it is not recommended to allow a bend radius that will be less than the thickness of the product. Ignoring this rule can lead to the formation of a crack in the structure of the material.
Of course, the range of processing procedures is much larger. So, for example, there is a whole layer of corrective methods that allow you to accurately simulate the shape of the product. Similar operations are performed with files, files and rasps. An even more critical segment of work is represented by assembly operations, which are performed after cutting, straightening and bending metal. Plumbing in this area is associated with the operations of connection, twisting, installation manipulations, etc. In installation work, pliers, ratchets, screwdrivers, the same hammers with pliers, as well as small fasteners and consumables are used. After all, do not forget that the listed processing operations are carried out with specific purposes for the further use of the product. these can be industrial areas, and auto repair shops, and household use. For example, at home, a restored piece of a deformed plumbing pipe or trimming a profile for a roof can be applied.
Cutting, straightening and bending of metals
The profile of locksmiths is constantly expanding and segmenting, which is associated with the emergence of new tasks. At the same time, the basic list of operations performed by specialists in this area is also preserved. The most common types of processing of this kind include cutting, chopping, straightening and bending of metals for various purposes. Such operations are performed by plumbers, toolmakers, and automotive craftsmen.
When choosing a suitable method for processing a metal workpiece, one should focus on the conditions of work and the capabilities of the tool. The characteristics of the workpiece itself deserve special attention. It’s one thing. straightening and bending of metals with a soft structure, and the other for cutting tool steel with a thickness of more than 20 mm. In each case, the means corresponding to the technical and operational parameters must be used. It will also be useful to take into account auxiliary ways of supporting a processing operation. These include the same thermal effect, melting, the use of slipways, compressor units and other equipment that facilitates the work performed.