How to properly cut thick metal with gas. Metal cutting with an oxygen-propane cutter. Gas cutting equipment

Advantages and disadvantages
Necessary equipment
Preparation for work
Getting started
Nuances of metal cutting
Precautions

Compared to gas welding, gas cutting requires much less skill from a person. Therefore, mastering a gas torch is not that difficult. It is enough to understand how to do it correctly. The most widespread in our time are propane cutters. They use propane and oxygen together, since their mixture gives the highest combustion temperature.

Advantages and disadvantages

The advantages of cutting metal with propane over other methods are obvious:

Gas cutting is used when you need to cut rather thick metal or cut something according to templates, when a curvilinear cut is required, which simply cannot be done with the same grinder. A gas cutter is indispensable if there is a need to cut a disc from thick metal or punch a blind hole by 20-50 mm.
Light weight and ease of use of the torch is another indisputable advantage. Those who have worked with gasoline analogues know how heavy, clumsy and noisy they are, vibrate strongly, forcing the operator to exert considerable effort during work. Gas models are free from all these disadvantages.
In addition, cutting metal with gas allows you to work 2 times faster than when using a device with a gasoline engine.
Propane is much cheaper not only than gasoline, but also other gases. Therefore, it is beneficial to use it for large volumes of work, for example, when cutting steel for scrap.
The cut edge with propane cut is slightly worse than with acetylene cutters. Nevertheless, the cut is much cleaner than that of gasoline burners or grinders.

The only drawback of gas cutters (including propane ones) can be considered the limited range of metals that can be cut with their help. They can only handle low and medium carbon steels, as well as ductile iron.

Cutting high-carbon steels with gas is impossible, because their melting point is quite close to the flame temperature. As a result, the dross is not emitted as a pillar of sparks with back side sheet, but is mixed with molten metal at the edges of the cut. This prevents oxygen from reaching deep into the metal to burn through. When cutting cast iron, the process is interfered with by the shape of the grains and the graphite between them. (An exception is ductile iron). Aluminum, copper and their alloys cannot be gas cut either.

It should be recalled that grades from 08 to 20G belong to low-carbon steels, grades from 30 to 50G2 to medium-carbon steels. In the designations of grades of carbon steel, the letter U is always placed in front.

Necessary equipment

To cut metal with gas, you must have one cylinder of propane and one oxygen, high pressure (oxygen) hoses, the cutter itself and the mouthpiece of the required size. Each cylinder must be equipped with a reducer to regulate the gas supply. Please note that the thread on the propane cylinder is reverse, so it is impossible to screw another reducer onto it.

The design of gas equipment for cutting metal from different manufacturers differs slightly. Usually they all have 3 valves: the first is for the propane supply, followed by the regulating oxygen valve, and after the cutting oxygen valve. Most often, oxygen valves are blue, the same ones that open propane, red or yellow.

The metal is cut using a jet of hot flame that is generated by the cutter. During the operation of the apparatus in a special mixing chamber, propane combines with oxygen, forming a combustible mixture.

The propane cutter is able to cut metal up to 300 mm thick. Many parts of this device are replaceable, so the device can be quickly repaired right at the workplace if it breaks down.

It is very important to choose the right mouthpiece. When choosing it, one should proceed from the thickness of the metal. If the object to be cut consists of parts of different thickness, which varies from 6 to 300 mm, you will need several mouthpieces with internal numbers from 1 to 2 and external numbers from 1 to 5.

Preparation for work

Before starting work, it is imperative to inspect the device to make sure that the torch is fully functional. Then follow these steps:

The first step is to connect the hoses to the cutting machine. Before attaching the sleeve, you need to purge it with gas to remove debris or dirt that has got there. The oxygen hose is attached to the right-hand thread with a nipple and nut, the second (for propane) hose to the left-hand thread. Remember to check the torch passages for leaks before attaching the gas hose. To do this, connect the oxygen hose to the oxygen connection, and the gas connection must remain free. Set the oxygen supply to 5 atmospheres and open the gas and oxygen valves. Feel the free fitting with your finger to see if air is leaking. If not, clean the injector and blow out the torch passages.
Next, check the detachable connections for leaks. If you find a leak, tighten the nuts or replace the seals.
Do not forget to check how tight the mountings of the gas reducers are and whether the pressure gauges are in good working order.

Getting started

We set 5 atmospheres on the oxygen reducer, and 0.5 on the gas reducer. (Typically a gas to oxygen ratio of 1:10.) All torch valves should be closed.

To work with a cutter, set 5 atmospheres on the gearbox, and 0.5 atmospheres on the gas one.

Take the cutter, first open the propane a little (by a quarter or a little more), set it on fire. We rest the nozzle of the cutter against the metal (at an angle) and slowly open the regulating oxygen (do not confuse with the cutting one). We adjust these valves one by one to achieve the flame strength we need. When adjusting, we open alternately gas, oxygen, gas, oxygen. The strength (or length) of the flame is selected with the calculation of the thickness of the metal. The thicker the sheet, the stronger the flame and the higher the oxygen consumption with propane. When the flame is adjusted (it turns blue and crown), the metal can be cut.

The nozzle is brought to the edge of the metal, it is kept 5 mm from the object being cut at an angle of 90 °. If a sheet or product needs to be cut in the middle, the metal should be heated up from the point from which the cut will go. We heat the upper edge up to 1000-1300 °, depending on the metal (to the temperature of its ignition). Visually, it looks as if the surface has started to "get wet" a little. Warming up takes just a few seconds (up to 10). When the metal ignites, open the cutting oxygen valve, and a powerful, narrowly directed jet is applied to the sheet.

The valve of the torch should be opened very slowly, then the oxygen will ignite from the heated metal on its own, which will avoid a blowback of the flame, accompanied by a pop. We slowly move the oxygen stream along a given line. In this case, it is very important to choose the right angle of inclination. It should be 90 ° first, then have a slight deviation of 5-6 ° to the side, reverse direction cutting. However, if the thickness of the metal exceeds 95 mm, a deviation of 7-10 ° can be allowed. When the metal has already been cut by 15-20 mm, it is necessary to change the angle of inclination by 20-30 °.

Nuances of metal cutting

You need to cut the metal at the right speed. The optimal speed can be determined visually by how the sparks fly. A stream of sparks at the correct speed flies out at an angle of approximately 88-90 ° to the cut surface. If the sparks are flying in the opposite direction of the torch's motion, the cutting speed is too slow. If the angle of flow of the sparks is less than 85 °, this signals an overspeed.

When working, it is always necessary to be guided by how thick the metal is. If over 60 mm, it is better to place the sheets at an angle to ensure the drainage of slag, and do the job as accurately as possible.

Cutting thick metal has its own characteristics. You cannot move the torch before the metal has been cut to full thickness. By the end of the cutting process, it is necessary to smoothly reduce the advance speed and make the cutter tilt angle 10-15 ° more. It is not recommended to stop during the cutting process. If the work is interrupted for some reason, do not continue cutting from the point at which you stopped. It is necessary to start cutting again and only in a new place.

After finishing cutting, first shut off the cutting oxygen, then turn off the regulating oxygen, and last turn off the propane.

Surface and shape cutting

Sometimes it becomes necessary to cut through the metal not through and through, but only to create a relief on the surface by cutting grooves on the sheet. With this cutting method, the metal will not only be heated by the torch flame. The molten slag will also serve as a heat source. As it spreads, it will heat the lower layers of the metal.

Surface cutting, like conventional cutting, begins with the desired area warming up to the ignition temperature. By turning on the cutting oxygen, you will create a hot spot for the metal, and by moving the torch evenly, you will ensure the stripping process along the specified cut line. In this case, the cutter must be positioned at an angle of 70-80 ° to the sheet. When supplying cutting oxygen, tilt the torch to create an angle of 17-45 °.

Adjust the dimensions of the groove (its depth and width) with the cutting speed: increasing the speed, decreasing the size of the groove and vice versa. The depth of the cut will increase if the angle of inclination of the mouthpiece increases, if the cutting speed decreases and the oxygen pressure increases (of course, the cutting). The width of the groove is controlled by the diameter of the cutting oxygen jet. Remember that the depth of the groove should be about 6 times less than its width, otherwise sunsets will appear on the surface.

You can cut a shaped hole in the metal as follows. First, we outline a contour on the sheet (when marking a circle or flanges, the center of the circle should also be noted). Hole punching should be done prior to cutting. It is always necessary to start cutting from a straight line, this will help to get a clean cut on the curves. You can start cutting a rectangle anywhere except at the corners. Last but not least, the outer contour should be cut. This will help to cut the part with the smallest deviations from the intended contours.

Precautions

Cutting metal with gas involves some risk, so you must strictly adhere to safety rules. Let's start with protective clothing, which should include: a fireproof suit and arm protectors with the same impregnation; a welder's mask made of non-combustible plastic with a headgear; work shoes with high sides. It is also recommended to wear a respirator. Why breathe smoke and dust? All these measures were not invented by chance, and should not be neglected. For example, a situation may arise when thick metal is not immediately blown through, and molten splashes will fall on you.

In the process, do not forget to follow the indication of the reducers on the cylinders. Remember not to start cutting if the hoses are cracked, ripped, or seated. Some craftsmen connect the joints with a tube made of aluminum or brass. However, it's best not to risk it. Please note that iron pipes cannot be used for this purpose categorically, since iron can give a spark.

The most important thing to know when working with torches is that propane is flammable, oxygen is oil. If oxygen comes into contact with any oil, an explosion will occur. To avoid disaster, do not touch the oxygen cylinder with oil-stained gloves or clothing. Do not leave oiled rags nearby.

Remember that cylinders should be located 10 m from the workplace and 5 m from each other. All gas from the cylinder cannot be spent in any way.

Sometimes in the process of work, emergency situations arise. Don't get lost. For example, if your oxygen hose falls off or breaks during cutting, do not be alarmed. Usually, fear arises from the fact that it happens unexpectedly and loudly. It is necessary to immediately shut off the propane supply on the torch, then close both cylinders. It happens that when lighting a flame and adjusting the torch, the flame suddenly disappears, emitting a pop. Simply close the torch valves and reignite the flame.

Cutting metal with a gas torch consists of two main stages:

at the first stage, the alloy is heated to the required operating temperature. For this, a flame of a burning mixture of gas and oxygen is used;
on the second, the metal is burned in a stream of oxygen.

How to use a gas torch: igniting gas and heating metal

Gas cutter brand NORD-S

Before igniting the torch, make sure all fittings are tight.

Next, the acetylene valve is opened on the torch and oxygen is allowed to leave the mixing chamber. When you hear that the acetylene is slowly coming out, turn on the valve. The burner is ignited with a special tool.

Lighters

The lighter should be positioned in front of the nozzle so that its inside touches the mouthpiece. The lighter creates sparks that will ignite the acetylene.

A small yellow flame forms in front of the mouthpiece. Using the gas supply valve, we increase the flame length to about 250 mm. We make sure that the torch starts at the mouthpiece itself.

If the fire will "jump" or break away from it, then you should reduce the gas supply.

Smoothly open the front oxygen valve. It is necessary to supply as much oxygen as is necessary for the complete combustion of the acetylene. When this happens, the fire will change from yellow to blue. Thereafter, the oxygen supply should be increased until the inner blue flame tongue diminishes and contracts.

We continue to open the oxygen valve and increase the size of the torch until the length of its internal flame is slightly greater than the thickness of the material being cut. If you hear a sound similar to "puffing", or notice that the blue flame has become unstable, then you should reduce the oxygen supply. It is reduced until the flame becomes stable, and a clear cone is formed inside.

The cutter is brought to the workpiece so that the inner flame touches its surface with its very tip. Heating is continued until a "pool" of molten metal has formed at the point of contact. The tip of the flame should be kept still at a distance of 10 mm from this “pool”.

Gas cutting for metal: shortened and lever from the company Nord-S

How to cut with a gas cutter (technology)

We gradually increase the stream of oxygen, which ignites the molten metal. If a violent process has begun, and the steel has caught fire, then you can gradually increase the oxygen pressure (until the fire will cut through the material). If the reaction does not start (the metal is not heated), then oxygen should be added and heated.

We began to cut the metal and slowly move along the cutting line. All processed products are blown away to the rear of the cutting area. If this flow slows down or returns, then reduce the cutting speed or stop and warm up the material.

For many years, mankind has been using metal products. Some of them require pre-cutting for the subsequent application of small pieces.

One of the methods of cutting metal is gas cutting. The technology of this method has its own characteristics and equipment used.

Gas cutting of metal used to be very popular in repair work... This cutting method was the main one.

The spread of the application of this method is justified by a number of features:

Expands the ability to cut thick workpieces;
Does not require power supply from the mains;
High performance;
The ability to perform complex operations;
Manual and automatic operation.

This method allows you to process carbon and alloy steels, titanium alloys, products from brass, cast iron, lead, bronze, aluminum.

Flame cutting can be classified into categories based on the nature of the cut:

Separating - characterized by the execution of a through cut, which divides the workpiece into the required number of parts;
Surface - involves the removal of the surface layer of the workpiece, forming the necessary channels, slots and other structural sections;
Cutting with a spear - involves burning the surface to be machined to obtain openings or blind holes.

Thus, the method allows you to procure a variety of metal parts, to weld pipes of different diameters.

Technological stages

Flame cutting technology consists of the following steps:

Heating the metal blank with a heater to a temperature of 1100 ° C;
Introduction of oxygen flow into the treatment zone;
When oxygen comes into contact with a metal surface, ignition occurs;
Under the influence of ignition, the workpiece begins to "burn", forming the desired processing result.

The billet is heated under the action of a mixture of combustible gas and technical oxygen.

A propane-butane composition, acetylene, natural, pyrolysis or coke oven gas is used as a combustible gas. The most popular are acetylene and propane-butane compositions.

In the process of ignition, the reaction of formation of oxides takes place. They are blown out of the working area by a stream of oxygen. Metal oxidation occurs only in the areas of oxygen flow, which excludes the ingress of reaction products into the metal. For the continuity of the cutting process, it is required to provide a jet of heating composition in front of the oxygen jet.

It should be borne in mind that the melting point of the metal being processed must be greater than the ignition temperature in oxygen. Otherwise, metal combustion will not occur.

And also the melting index of the formed oxides should be lower than the corresponding indicators for the metal. This is justified by the fact that otherwise the resulting products will not leave the working area, but will remain on the surface of the workpiece. When choosing a workpiece, you need to focus on the thermal conductivity of the metal. The lower it is, the easier the ignition will take place.

Cutter - cutting device

The change of stages of the cutting process is provided by special equipment. It implies an appropriate stable structure for the stability and safety of the operations being conducted. One of the main components is a gas cutter. There are also nozzles for welding and melting, used with this equipment.

Cutting assumes the accuracy of dosage and connection of the gas mixture with oxygen. And also this device provides a heating flame and the introduction of oxygen into the work area.

Known cutters are injection-type devices that work with steel up to 30 cm thick. This cutter connects the cutting and heating unit. The heating unit includes valves responsible for supplying the gas mixture and oxygen. And also it contains an injection cell, a mixing chamber, a feed tube, an external mouthpiece.

The cutting unit is formed by a pipe for outputting the cutting oxygen stream, a control valve, and an internal mouthpiece.

The gas mixture and oxygen move to the torch through different inlets. Oxygen moves to the injector and mouthpiece to create a cutting jet. After the injector, oxygen is fed into the mixing chamber, where the gas is also directed through its inlet.

After mixing, the composition ends up in the mouthpiece, which is responsible for the formation of a heating flame. The valves allow changing flows.

Cutters can be divided according to the area of \u200b\u200buse into:

Manual - used for manual cutting;
Machine tools - are used on cutting machines and machines.

There are also non-injection cutters and tools for supplying combustible mixtures of different composition:

Acetylene;
Propane, butane and propane-butane;
Universal;
Natural gas cutters;
Kerosene cutters - have an evaporating unit for the production of vapors of gasoline, kerosene and gasoline-kerosene mixture.

When you start using any cutter, it is first checked that it is working properly. Then the device is purged with oxygen.

Applied equipment

Cutting metal with gas involves the use of many basic and additional tools. In addition to the cutter, the gas-cutting equipment consists of:

Reducer - used to reduce the pressure of the directed gas to the required value. It contains two pressure gauges for measurements at the inlet and outlet.
Pressure change tool.
Gas and oxygen cylinders.
Connecting hoses.

The reducer provides pressure regulation and automatic maintenance of the achieved value at a constant value. The reducer can be formed by one or two chambers. If there are two chambers, the device rarely freezes, which affects the reliability and sequence of operations.

The cylinders are made of steel. The volume is 0.4-55 dm3. They are equipped with a shut-off valve. Depending on the composition (oxygen or gas), valves of various designs are provided. Color differences and inscriptions have been developed for the composition inside the cylinder.

In the case of cutting with the use of special machines, it is assumed that the equipment is stationary. In this case, auxiliary devices are used:

Cutting table;
A mechanism for the removal of the resulting slag and waste;
Workpiece moving system;
Ventilation system.

In addition, other gas-folding and working posts are provided.

Equipment for cutting metal on a large scale includes the following components:

Carrying part;
Cutter (can be one or several);
Drive device;
Remote Control.

On large manufacturing enterprises portable cutting machines are often used. The principle of their operation does not differ from stationary devices.

Instructions

First warm up the cutting area to a certain temperature. Be aware that there may be a heating value for each type of metal. Basically, it varies from 300 to 1300 degrees. The preliminary procedure will allow the oxidation of the metal in oxygen to begin. As a result, a flame of acetylene or substitute gases appears. After that, you can let in oxygen, which cuts the metal and immediately removes oxides. Make sure that the heating flame is continuous, for this it must be a jet of oxygen.

Whenever possible, select low carbon steels with a substance content of less than 0.3%. They are the easiest to cut through. For high carbon metals, you will need to resort to cutting with the addition of special fluxes.

Pay attention to the flame, its length should depend on the thickness of the metal. Thus, a substance with a thickness exceeding 400 mm must be cut with a flame that penetrates to the full depth, containing a large amount of acetylene. Otherwise, a normal flame can be dispensed with.

Set the direction of the flame to the edge of the metal, it is very important from the very beginning the correct angle of inclination. Aim the heating flame at the edge of the metal until you reach the desired reflow temperature.

Follow a specific metal cutting procedure if you want to saddle holes. In this case, first heat the edge of the material, then turn off the flame and only then start the cutting oxygen supply. Open the valve on the torch very slowly, this will ignite the oxygen flame from the molten metal and avoid backfire, popping.

Pay attention to the thickness of the metal: if it exceeds 50 mm, keep the sheets at an angle, so you can ensure the drainage of slag formations and do the job as accurately as possible.

Choose a mouthpiece based on the thickness of the metal: if it varies between 8-300 mm, you will need a mouthpiece with an outer 1 to 5 and an inner 1 to 2.

You will be able to correctly carry out the process of cutting metal, initially choosing the correct angle of inclination of the torch during cutting, determining the point from which you will start cutting, maintaining the correct angle of the flame (no more than 5 degrees of inclination, with a metal thickness of more than 100 mm, a deviation of 2-3 degrees is allowed ) by choosing the right gas and the right mouthpiece.

note

The whole process must be carried out in special clothing... Protect your eyes with special glasses, wear gloves and a suit.

Useful advice

When you complete the process, turn off the gas cylinders gradually. Remove oxygen first, then propane.

Sources:

how to cut metal

A paper cutter is an essential feature of any printing house and almost any office. And the selection of these products in stores is impressive. However, choosing the right model for yourself is a very difficult task. There are roller cutters, saber cutters, guillotine cutters - these are three main types. Unfortunately, not all paper cutter buyers are happy with the choice. And all because they look primarily at the price, not paying attention to the more important selection criteria. To make your choice, first find out what to choose from.

Instructions

Roller cutters are the simplest and most affordable. The cutting surface is a sharpened metal disc that moves over the counter knife along the base of the device along the rod. In cheap models, the edge of the base often protrudes with a counter knife. Roller cutters can handle large paper sizes and are renowned for their great precision. As you can see, such models are quite simple, due to which they are also very reliable and easy to use. Their only drawback is low performance.

Reciprocating cutters are more productive than roller cutters. In them, as is already clear from the name, a sharp knife is used for cutting - "saber". It attaches to the base of the cutter with one side and a handle on the other. By pressing on it, you move the knife down, and it comes into contact with the counter knife, the role of which can also be played by the edge of the base.

While a roller cutter can cut an average of no more than 10 sheets at a time, a saber cutter can handle 50 sheets of paper. Unfortunately, saber cutters have more drawbacks than their roller "counterparts": often the bottom sheets are cut along a curve, since the knife is behind it; the paper fluffs up when cut, resulting in jagged edges.

To level these, you do not need to save on a reciprocating cutter - make sure that it is equipped with a reliable pressure device and a knife made of stainless steel. By the way, for the most part, the cost of a saber cutter is determined by the knife.

For guillotine cutters, some unknowingly give out saber cutters. Undoubtedly, they are somewhat similar, but the differences between them are much more than similarities. Guillotine cutters are equipment for professionals. They are able to cut a stack of paper several tens of centimeters thick. In addition to paper, guillotine cutters can cut other materials, both similar in structure to paper and very different. And they usually buy such machines in printing houses and large offices. The equipment is, of course, not cheap. Nevertheless, if you decide to acquire such a cutter for your printing house, buy at least one more roller - it can still perform such work for which its guillotine "relative" is not intended.

Office cutters are suitable for most common operations. Therefore, they are widely used in small and medium-sized offices, as well as at home (by amateur photographers, for example). These cutters include most roller cutters as well as some saber cutters. The class of cutters is characterized by low productivity and low price. Remember, however, that if the price is too low, most likely the knife is made of low-quality metal, and you should not buy such a cutter.

Finally, professional cutters are devices that are primarily designed for printing houses. They can be not only guillotine, as some think. Roller cutters and saber cutters may well be professional, certainly equipped with very high-quality knives that ensure a flawless cut. These cutters are very reliable and provide the highest performance. Well, and at an impressive price, of course, they also differ.

Description

A dummy knife is great for making decor. The tool cuts plain paper, watercolor paper, pastels, and cardboard.

The knife consists of a handle made of wood, plastic or metal, and a blade. On sale you can find different models of tools that differ precisely in the shape of the blades. She may be:

with a pointed and jagged edge;
triangular;
rectangular;
sawtooth;
rounded.

The pointed blades have a 30 ° sharpening angle. For triangular, this parameter is 23 °. Such blades can also be used when working with wood, plastic.

How to choose a breadboard knife

When choosing a breadboard knife, pay attention to what material its handle is made of. It is recommended to purchase a tool with a metal handle. The plastic handle must be strong enough not to break under pressure. It is better to have a seal on the handle, it does not allow the hand to slide off.

Another nuance is the blade clamp, which is a metal knob covered with rubber. If it is made of plastic, it is better not to buy such a tool. It is not reliable, after a while a gap may appear in the mount and the blade will fall out.

How to use a breadboard knife

Cut with a breadboard knife in the following order:

Draw a diagram of the image from the wrong side of the material.
Start cutting with the smallest details. Then go to the central part. If there is a contour, process it last.
Cut through all the details, leaving none. In no case should you pull out any of them, this will ruin the work.
Use a ruler to make it easier to cut straight lines.
In the process of work, you can rotate the material with a pattern. This will make the job easier.
Choose a suitable background depending on the selected scene, the purpose of the cut and glue the work on it.

For safety reasons, do not give a dummy knife to children, let them use scissors. Use a mock-up mat in your work. This will allow the knife blade to stay sharp longer. At first, you can replace the mock rug with a stack of newspapers, a cutting board, a piece of linoleum, or glass.

Modern works made by cutting out of paper are called openwork (filigree) cutting, as well as paper graphics, cut images. In this technique, you can make napkins, postcards, panels, frames, decorations for windows, mirrors, etc.

So, gas cutting of metal is now the most popular. Why?

Because it is extremely simple to perform, you do not need to use any phase inverters (as in an electric cutter), you do not have to comply with the mandatory room standards (the presence of a central ground cable).

And practically all torches are mobile, that is, they can be transported by conventional transport.

When cutting, a gas torch uses two gases - directly oxygen, with the help of which the metal separation process is carried out, as well as a heater, which is most often propane or acetylene.

The heater heats the surface to be cut to a temperature of 1000-1200 degrees, after which a stream of oxygen is supplied. On contact with a heated surface, the jet ignites.

It turns out - a burning jet that easily cuts the metal. In this case, the most important thing is to maintain a continuous supply of oxygen.

If there is an interruption, the flame can simply go out, after which the surface will have to be heated again.

Standard oxygen cutting of metal is performed using the R1-01P torch. It is best suited for working with hardened steel, including cast iron!

This torch is not used as a welding machine.

But it is suitable for precise cutting of the pipe - for this, a special hinged pad RF7 is used, which is made of steel, but covered with a layer of tungsten.

By the way, recently, metal cutting has also been performed using a combination of acetylene and propane. But such equipment is used exclusively for working with high strength metals (for example, steel for copulating knives).

The equipment that supports this gas isn't cheap! So we won't talk about him especially ...

The modern technology of gas cutting of metal is somewhat different from the one described above. For example, when working with "light metals", temperatures of 1000 degrees Celsius and above can simply destroy the metal you are working with (melt and vaporize).

In these cases, the cutting itself is performed with simultaneous heating. The torch tip is pyramid shaped with 3 nozzles.

A heating mixture is supplied through two side ones, and a thin nozzle is mounted in the center for supplying oxygen under high pressure.

In modern cutters, oxygen is supplied under a pressure of 12 atmospheres! Simply put - even the skin can be damaged under a stream of air (meaning an unlit stream).

The flux that is formed during such cutting is either thrown out by the heating flame to the sides, or is burned directly through the entire metal (if through cutting is performed).

Don't forget that gas cutting metal has a big advantage over electric cutting. Which one?

No “torn” seam is created. And if you additionally use overlays (stencils, as professional welders call them), then the cutting seam is very neat!

But keep in mind that cutting metal with oxygen does not involve using metals that melt below 600 degrees Celsius. In this case, a simple removal of the top layer of metal, rather than cutting it, will be performed.

Standard technology oxygen cutting metal implies the use of a pilot-controlled torch. The gas supply is regulated by means of two valves (in some models - one common valve).

The cutter handle itself has two tubes that fit into the handle. The first handle supplies fuel for the heater, the second (usually the central one) supplies oxygen. That is, as many as 3 tubes are supplied to the main nozzle!

Through two, propane is supplied, through the third, oxygen. Older cutter models used two tips that worked in a similar way.

What is the gas consumption when cutting metal? It depends on the temperature to which the metal itself is heated during operation.

In a standard R1-01 cutter, an average of 10 cubic meters of oxygen and 0.7 cubic meters of acetylene are consumed in one hour of operation (when using propane, 1 cubic meter of fuel).

But in the P2-01 cutter, the consumption is much higher - 21 m3 of oxygen and 1.2 - acetylene! The heater consumption depends on the heating temperature and the plane that is cut.

The "older" torches also use the so-called nozzle direction, which also partially affects the flow rate (the closer to the oxygen stream, the larger the jet has to be supplied).

Gas cutting equipment

So, in Russia, since the times of the USSR, the P1-01 cutter was considered the most common. It is hand-held with an injection nozzle that produces a high pressure jet that cuts metal "like a hot knife like butter."

More powerful models are P2-01 and P3-01P. Their main difference is the size of the nozzle, the operating pressure of oxygen in the system, and the operating pressure of the heating mixture supply.

There are also stand-alone tables - these are gas equipment for cutting metal in automatic mode, which is produced without operator participation.

The control of such a table is numerical-programmed. That is, a person simply sets the cutting parameters.

Such oxygen cutting equipment is used exclusively on sheet metal where either straight cutting or arc cutting is performed.

It is worth noting that there are a huge number of models of these tables, but almost all of them are analogues of the AN-01, which was developed by Shepelev back in the USSR!

These, for example, are "Change", "Orbit", "Secator", "Quicky-E". All of them have an operating temperature in the range of 1000-3200 degrees Celsius. They work with both acetylene and propane heaters.

The Quicky models also use mixed - acetylene / propane heating. In this case, only a split nozzle is used. That is, acetylene is fed to one of them, and propane to the second.

By the way, it is worth noting that in such cutting, the heating mixture lends itself from the center (that is, from the oxygen stream).

Also, the so-called stationary torches for gas cutting of metal are also noted.

They differ from the mobile one, it is not difficult to guess, in that they are built into a special niche-machine, which the operator of the device can just move.

These cutters are more convenient to work with, but are very expensive. But their cutting power is more than enough to cut through a thick layer of high-strength metal!

This became possible due to the fact that in such cutters an additional blower is used, with the help of which both the heater and the oxygen stream are supplied under even greater pressure.

An additional compressor is powered by electricity, moreover - three-phase (380 volts). Because of this, it cannot be mobile! This cutter is used exclusively in professional enterprises.

Portable cutter - Gugark

Gugark is the most popular of these cutters.

By the way, gas-burner for cutting metal there are also two types - the so-called straight and bent:

The first is the one you are all used to seeing. Represents the letter G and works with the help of the operator's direction.
Well, the second, straight, is a nozzle-type burner that is used on cutting tables.

It is also worth noting that straight nozzles use twin tips to ensure that the nozzle angle is not disturbed one-to-one during movement.

By the way, keep in mind that each of the cutters has its own coefficient of work and power with each metal.

For example, when using the standard P1-01, to cut copper, a coefficient of 0.5 acetylene is sufficient, but for aluminum, as much as 0.7 is required.

Most of all, of course, will go to tungsten - as much as 1.4! In this case, the heating will be around 3800 degrees Celsius (use only specialized tips)!

Services popular on the market

If you need to cut metal, then the easiest way is to hire a craftsman or specialist who will provide you with the necessary services. After all, not every house in the garage has a cutter with two oxygen cylinders and a heater.

Moreover, working with such equipment is very dangerous without experience! If you do not know how, then it is better not to take on this business - entrust the work to professionals!

Well, on average, the price of gas cutting of metal consists of following indicators: the metal you will need to work with, the cutter used, the thickness of the metal, the quality and type of cut.

For example, conventional sheet cutting is the cheapest. Pipe cutting - it is much more expensive, since additional linings are used during such work!

But cutting in depth is an expensive pleasure, since it uses expensive equipment.

Moreover, if such work is performed “on the road”, it will be very expensive. Cars that can transport cutting stations need to be additionally refurbished.

Oxygen metal cutting - video:

Well, gas cutting sheet metal can be carried out even with a conventional gas soldering iron. If you are using aluminum or copper, then it should be enough for this job.

In some cases, you can use gas welding. But instead of carbon dioxide, propane, acetylene or butylene is supplied (not every gas welding supports the use of such a gas, be careful)!

The most expensive sheet metal cutting is the one that is performed along the prepared cutting contour. In this case, a CNC machine is used, the services of which are not paid cheaply!

By the way, if you need to do not cutting, but cutting, then in some cases it will be much easier and cheaper to use a knife for cutting metal, and not a gas cutter. You can learn more about this directly from the master you want to entrust the work to.

Now many enterprises offer on-site gas cutting of metal.

Here it is, assessed by the following parameters:

the metal with which you will need to work;
the complexity of the work;
used cutter.

It also takes into account how much time the work will take. On average, an hour of work of the master is paid for about 300 rubles. You can calculate in advance how much metal cutting services will cost you!

And finally, we should talk about those cases when poor-quality work is performed. Very often, many people use instead of acetylene - its cheap analogue is propane or propylene. Or they use cheaper cutters than they themselves announced.

For example, instead of P2-01, P1-01 or the like is used. This, by the way, is the most common problem! You can distinguish between the two cutters by visual inspection.

The P1-01 model has a double nozzle with a gold mount (golden color), while the P2-01 model has a steel mount (it has a black or copper tint).

By the way, the P1-01 cutter is not so expensive, so you can even get it! The average cost is in the range of 900-1000 rubles per piece. Well, of course, you will need to purchase two cylinders - with oxygen and a heater, and a transport cart.

On average, the entire set will cost you 3,000 rubles, no more. It will be enough for 3 hours of metal cutting. For home needs, this is more than enough.

And when working with a gas torch, be sure to follow the safety rules! And this is the use of a protective mask, overalls and gloves. Gloves are a must!

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