A chamfer is the surface of a product, which is formed during the processing of a rolled product or pipe by a bevel of the end edge of the material. A chamfer is necessary to prepare the edges of sheets, beams and pipes for welding.
The main types of chamfers are:
- "Gas". This is the cheapest type of pipe bevel due to its poor quality. However, this type is one of the most common. This chamfer is removed using . Chamfer "Gas" can be performed in the field. Its surface is usually with characteristic grooves, which are formed from a gas jet (propane or acetylene).
- "Plasma". Outwardly, this type of chamfer is practically no different from the "mechanics". It can also be attributed to the "factory". The "Plasma" chamfer is an air-plasma cutter, a compressor and, forcing the cutter to move strictly in a circle, when a certain chamfer angle is set.
- "Mechanics". This is a factory chamfer, the best quality. For cutting the chamfer "mechanics" are used and. In the pipe market, this chamfer is mainly used due to the high quality of the chamfer.
What is the purpose of chamfering? When welding blanks, the metal is melted, which subsequently ensures the connection of the edges with each other. If the thickness of the metal is more than 3-5 mm, obtaining a complete and high-quality connection becomes difficult. To obtain high-quality penetration, this type of processing is carried out: it allows you to create a so-called weld pool, which is filled with a welding compound during the welding process. It is important to remember that an edge prepared for welding is an edge with a chamfer and blunting (see the figure and symbols for it below).
Types of chamfers (methods of cutting edges).
There are three main ways of cutting edges for welding: Y-shaped, X-shaped, and J-shaped. Sometimes in some sources they are denoted by letters: V, K and U, respectively. Hereinafter, the above methods will be denoted by the letters: Y, X. J. Most often, a Y-shaped cutting of the edges is carried out, but there is also an X-shaped method. In special cases, when there is an increased requirement for the quality of the weld, a J-shaped chamfer is used, that is, a chamfer with a curved surface (not to be confused with edge curvature!).
In addition to the main ways of processing Y, X. J edges, there are a number of edge preparations. They are not so rare, and not everywhere you can find their description. For example, GOST 5264-80 describes a butt joint type with a broken edge bevel; symbol - C14.
The diagrams above show some examples of processing methods:
1: an example of a Y-shaped chamfering method;
2, 3, 4: examples of the X-shaped chamfering method;
5: Y-shaped processing of the ends of two pipes with their subsequent connection;
Chamfering methods.
Chamfering can be done in two ways: mechanical and thermal (table 1). Mechanical chamfering is performed using milling, beveling and edge-cutting machines. For thermal chamfering, flame cutting machines (stationary or portable) are used that perform plasma or oxy-fuel cutting. However, the mechanical method is more preferable, since it makes it possible to exclude changes in the physical and chemical properties of the material as a result of overheating. As you know, during heat treatment, a so-called heat-affected zone is formed. The heat affected zone is the carburization of the edge due to overheating of the material, which impairs weldability and increases the brittleness and brittleness of the edge. But, despite these shortcomings, the thermal method is quite common because of its simplicity and speed of use, and the relatively low cost of equipment.
Table 1. Advantages and disadvantages of thermal and mechanical methods of chamfering.
Table 1 says that thermal chamfering can be done quickly and cheaply. Of the processing methods described above, mechanical is still preferable, since it allows you to save the metal from overheating and from subsequent changes in physical and chemical properties. In the West, by the way, this method is called cold-cutting (cold working), that is, a type of processing in which there is no thermal effect on the metal, which means there are no changes in the chemical and physical properties of the metal.
Video footage:
1. Pipe cutting by gas cutting machine CG2-11G, simultaneous chamfering of the pipe is carried out by tilting the cutter at the required angle.
2. Chamfering from a 76x6mm pipe with a Mangust-2MT machine
3. Pipe chamfering with a TT series chamfer, and pipe chamfering with a P3-SD split pipe cutter
The SPIKOM group of companies offers to supply equipment for chamfering pipes and metal using all of the above processing methods (gas, plasma, mechanical).
Usually, when planing wooden blocks or narrow boards, it is often necessary to chamfer a small size from the edges of the workpiece, in order to reduce the sharpness of the corners, as well as to make them more beautiful. To do this under normal conditions, you have to hold the workpiece with a planer at an angle of about 45 degrees, which is not very convenient, especially when you work with an electric planer, which is many times heavier than a manual one. You can solve this problem with the help of your special device, which will look like a longitudinal corner, where the bar will be placed, which will be further processed, and its edge will be just at the top, which is convenient for processing.
This arrangement of the workpiece in a homemade fixture will also help for planing faceted and round bars, as well as wooden handles that are inconvenient to process on a flat surface. The author of the homemade product thought about making such a device, since it became necessary when he was planing blanks for the handles of shovels, because with such a device the work was completed faster, and it was also much more convenient to work this way.
In order to make this device, you must:
Two wooden planks 2 cm thick, 4 cm wide and 6 cm wide, and 2 m long.
Wooden plank 2 cm thick, 5 cm wide, and 50 cm long.
Wood screws 4x50 mm.
Drawing and measuring tools (pencil, tape measure and square).
Awl.
Electric jigsaw with a file for a figured cut.
Electric drill-driver.
Drill for metal with a diameter of 4 mm.
Spherical cutter for wood.
Cross (shaped) bit RN2, for screwdriving.
Sandpaper.
When all the materials, as well as tools, are available, then you can proceed to the most interesting, this assembly process.
Step one.
First of all, you need to decide on the dimensions, you can use the dimensions that are given here, but if your workpiece is large, then simply increase the size of all the components to the required one. Using a pencil, we mark a bar 6 cm wide, then using a screwdriver and a drill, we drill holes along its entire length, on one side there are 5 or 6 holes for screws, as a rule, the more, the better, and more reliable.
Step two.
Having placed the bar on the opposite side with the help of a drill installed in the screwdriver chuck, we increase the dimensions for the screw heads, using a spherical wood cutter.
After we have increased the holes for the hats, we insert screws into these holes and screw our bar to the end of another bar 4 cm wide.
What should happen at this stage can be seen in the photo, this is the so-called wooden corner, its length is 2 m, made in order to have a margin in length used in the processing of blanks, thereby increasing the range of application, since you do not have to combine sizes, then small, then large fixtures, and it’s easier and more practical to make one, but more authentic.
Step three.
Using a jigsaw, we cut out a smaller workpiece from a plank, which will be the supporting part, with which the fixture will be held on a flat surface, this process requires sufficient accuracy and accuracy, for better accuracy, use a special corner stand on the jigsaw, which will help in creating even cuts. When working with a jigsaw, be extremely careful and do not forget to wear safety glasses and gloves, protecting yourself from accidental sawdust and wood dust getting into your eyes, and also protecting you from slipping out of the hands of the tool.
Step four.
The previous blank, the role of which is to hold our corner part, must be drawn, the lines must correspond to an angle of 45 degrees, as in the main part, for a better match, attach the future support and circle with a pencil. To fix it, you need to drill holes for the screws, in this case there will be three of them, which is quite enough, we select the drill according to the diameter of the screws so that the thread passes without difficulty.
Step five.
Then we tighten the screws with a screwdriver, that is, we fasten this workpiece to the end of our corner fixture, try not to overdo it with the twisting force so as not to damage the support and form a crack in it.
The rest of the bar will also benefit, we make the same blanks from it using a jigsaw, you will need two of these.
We supplement the corner with two more supports, which will make it much more stable, and it will also acquire a large workload, which is also important during processing. We fasten them in the same way as the first support.
Step six.
The back of the fixture must be drilled on each side, while using a screwdriver with a drill, the diameter of which is equal to the thickness of the screw, for strength we make two holes on each side to prevent turning.
The place of the holes, as in the previous stages, must be processed with a spherical wood cutter in order to drown the screw heads and thereby eliminate accidental engagement.
Step seven.
Armed with a screwdriver and a bit for driving screws, we twist the screws into blanks.
Next, we move on to more precise processing, for this we use sandpaper, as usual we start with a larger one, gradually reduce the size of the grit as we approach the finish of grinding.
On this, our home-made device is ready, now we will consider it from all sides for a full assessment.
This is what its back looks like.
And so is the front.
After you make such a device, you will have the opportunity to process bars without any difficulties and inconvenience, whether it be a wooden handle or a blank with square edges.
Chamfering a board can be done in a variety of ways. Two of them are most common: with the help of a manual and with an automatic tool. The negative side of the use of hand tools (various planers) is considered to be a high degree of injury risk, as well as a catastrophically low pace of work. Of course, automatic and semi-automatic milling machines are ideal for solving the indicated goals.
On the website http://www.zaoportal.ru/product/view/111 you can purchase a professional chamfering machine. The main reason why home craftsmen avoid buying such equipment is the apparent difficulty in operation. In fact, setting up and using it for its intended purpose does not cause any difficulties even for a novice user.
Initially, it is important to choose the right type of cutter. There are several types of bevels. Choose the one that suits your specific task. Not always a suitable cutter is included with the cutter.
But it won't be hard to get one. Cutters of this kind are freely available in tool stores and cost a penny.
Preparing the router for work is as follows:
- a hose from a vacuum cleaner is placed in the waste disposal socket;
- the position of the cutter is adjusted;
- the milling cutter is fixed in a given position;
- horizontal guides are installed.
With the addition of a vacuum cleaner, work is much easier. When processing wood, there is practically no waste left.
Initially, the cutter height adjustment knob must be turned until a characteristic click is heard. The depth adjuster pulls out 3 mm downwards. Then he goes down on his head. Thus, we get the "zero" position of the cutter.
Now, by turning the height adjustment knob, you can quickly and without much difficulty change the position of the cutter by 5, 10 mm.
Router guides for correct chamfering should also be adjusted. This is achieved quite simply - it is only important to tighten the nuts on the guides to the point where the router will slide along the surface to be treated, as if on rails.
Chamfer: what is it and why is it needed?
This is an edge obtained in a special way on the end surface of a metal sheet or on a pipe wall, beveled at a certain angle.
Main destination - preparation of rolled metal for further welding work.
Why is chamfering necessary?
The processing of the ends of the sheet or pipe walls is needed for:
- Good penetration and reliable connection of welding seams
- Reduced welding time
- Prevention of injuries of employees due to sharp corners of the product
- Simplification of the forthcoming installation of the erected metal structure
- In order not to carry out manual grinding of the edges of the edge of the sheet or pipe
If chamfering is not performed, then in products whose thickness exceeds 5 mm, the welding seam may disperse over time and the structure will lose strength.
Chamfering Angle
Chamfering Angle from the edge of the sheet or pipe is selected based on the design features of the product or the task of welding. As a rule, the standard chamfer angle for metal sheet profiles is 45°, for pipes - 37.5°.
There are three ways to cut the edge from rolled metal:
- Y-shaped way;
- X-shaped;
- J-shaped (another name is a "glass" chamfer);
- Also, in the technical literature you can find another letter designation: V, K and U-Chamfer.
- X-shaped;
Features of different types of chamfers
- The most common way of bevelling in production is the Y-shaped method and the X-shaped one.
- For a high-precision welding seam (for example, on products of complex design), a chamfer with a curved surface is used.
- J-chamfers are made using special automatic bevelers. This method creates a larger weld pool than other methods.
- For a high-precision welding seam (for example, on products of complex design), a chamfer with a curved surface is used.
Other types of edge cutting(butt type of connection with a broken edge) is not used so often in production.
Features of the chamfering process
For cutting edges on a metal product, special units are used - bevelers, differing in the method of cutting into three types (air-flame, mechanical and gas-oxygen equipment).
The cutting process is as follows:
- With the help of clamps, the beveler is attached to the edge of the sheet or the inside of the metal pipe.
- Next, the required sharpening angle is set.
- When the machine is turned on, the cutting head is brought to the product and the chamfering process takes place.
- After the end of the work, the cutter returns to its original position.
- After cutting the chamfer, the working surface of the product is considered prepared for further welding.
- Next, the required sharpening angle is set.
When cutting a chamfer, a welding tank (bath) is formed, where the hot welding composition is collected. The edge with a chamfer has a certain bluntness of about 3-5 mm. When the container is filled with welding compound, the blunt area melts itself. Due to this, the desired tightness of the seam is achieved and additional reliability is created.
Edge cutting methods
Currently, two methods of edge removal are used in production: thermal and mechanical.
Mechanical chamfer is considered the highest quality, since this method is performed on special equipment - beveling machines (edge cutters), milling machines, bevelers and other devices. The advantages of this method are as follows:
- After chamfering, the product retains its structure and does not lose its physical and chemical properties
- The mechanical method provides high tightness and reliability of future welding seams
- Saving time.
thermal method- air-plasma chamfer and gas-flame chamfer. Air-plasma cutting of edges allows you to get the appearance of the chamfer close to the factory (or mechanical chamfer). However, it requires a perfectly smooth surface of the sheet or pipes at a certain angle. In many industries, this type of chamfering is the main one because of the economy and high speed of processing products. It is carried out on special plasma-cutting equipment.
Gas-plasma chamfer cutting does not require special conditions for implementation and is characterized by low cost. But the quality of the cut is lower than with the mechanical or air-flame method. Often such chamfer cutting requires additional machining. This method is used for artisanal processing of used pipes. Using the thermal method of chamfering (gas-plasma and air-plasma chamfering), a section with changed physical and chemical properties (thermal influence zone) appears in a metal product due to overheating. This negatively affects the tightness and reliability of future welds and the strength of the structure itself.
Mechanical chamfering preserves the properties of the product and does not affect the quality of future welding work. Mechanical chamfering is a kind of guarantor of the quality of processing metal products before welding. The only "minus" of this method is the high cost of the units and the laboriousness of the work.
You can find out the cost of mechanical bevelers by phone ☎
Hello to all do-it-yourselfers!
When planing wooden blocks and narrow boards, it is almost always necessary to remove small bevels from the ribs in order to dull them to one degree or another. However, for this you have to hold the planer obliquely, approximately at an angle of 45 degrees, which is not always convenient, especially when working with electric planers.
You can get out of this situation if you make a special device in the form of a long longitudinal corner, in which the processed bar would be laid and thus the edge from which you want to chamfer would be on top.
In addition, such a device could also be used for planing faceted and round wooden blanks (for example, handles for garden tools: shovels, pitchforks, rakes, etc.), which are very inconvenient to plan on a flat surface.
I thought about making such a device, just when I was planing blanks for the handles of shovels (see my article ""), since with such a device my work would go much easier and faster.
As a result, I decided to make this device, for which I needed the following accessories:
Materials and fasteners:
Two wooden planks 2 cm thick, 4 cm wide and 6 cm wide, and 2 m long.
Wooden plank 2 cm thick, 5 cm wide, and 50 cm long.
Wood screws 4x50 mm.
Tools:
Drawing and measuring tools (pencil, tape measure and square).
Awl.
Electric jigsaw with a file for a figured cut.
Electric drill-driver.
Drill for metal with a diameter of 4 mm.
Spherical cutter for wood.
Screwdriver bit PH2, for driving screws.
Sandpaper.
Operating procedure
First, we mark a bar 6 cm wide, and drill along its entire length, on one side 5 or 6 holes for screws.
On the opposite side of the plank, countersink these holes for the screw heads using a spherical wood cutter.
Then we insert screws into these holes and screw our bar to the end of another bar 4 cm wide.
As a result, we get such a wooden corner 2 m long.
After that, using an electric jigsaw, we cut out such a blank from a short bar.
It will serve as a stopper for planed blanks, and at the same time, a support for our device.
We also mark this workpiece and drill three holes for the screws in it.
And then with screws, we fasten this workpiece to the end of our corner fixture.
From the remaining piece of the plank, we cut out two more such blanks with an electric jigsaw.
We will screw them to the back of our device, where they will serve as additional supports.
In the very back of the fixture, we drill two holes for the screws on each side.
We also countersink the upper parts of these holes with a spherical wood cutter in order to drown the screw heads.
Now we screw our blanks with screws.
All elements of the fixture, and especially the ends, are processed with sandpaper.
And now our device is ready!
This is what its back looks like.
And so is the front.
Now on this device it will be possible to process the bars.
Here, for example, I put a blank bar for the shovel handle into this device - rear view.
And this is the front view.
But the bar is not square, but rectangular in cross section. Now it will be quite easy to chamfer with such bars.
But I put in a fixture, a purchased handle for a shovel, round in section.
Such round blanks will now also be very convenient to process in this fixture. Moreover, they can not only be planed, but also carry out other types of processing, for example, drilling holes in them or sawing them.
Well, that's about all! All for now and convenient devices in the work!