How to cut metal in hard to reach places
Metal cutting is a method of processing sheet, cast and sectional workpieces, which consists in cutting them into parts with special tools.
Workpieces can be cold and hot.
- In the first case, you use tools to cut the metal mechanically. various saws, scissors, etc. д.
- During hot cutting the material melts in the place where it is affected by the tool. Droplets are removed by the gas stream. This processing method involves the use of more complex equipment: autogenous cutting machines; machines for plasma, oxygen, laser cutting, etc. п.
Professional and industrial metal cutting tools
Professional metal cutting tools are used for processing workpieces in industrial conditions.
Tools and machines for mechanical cutting
Mechanical cutting has the following advantages:
The main disadvantage. only straight cuts can be made mechanically.
- Angle grinders are most often used for cutting long products of small and medium diameters. Using angle grinders, rebars, angles, and tubes of square and round cross-section are made. The method is notable for its low productivity, but the amount of waste is minimal.
Consumable material for metal processing by angle grinder. abrasive and diamond discs.
- Circular saws. Can be used to make angled cuts. The advantages of this method are high precision and quality. The disadvantages. limited by the depth of cut, a large amount of waste.
Photo : cutting metal with a circular saw
- Guillotines. Billets are cut into parts by method of cutting. This method of processing is considered the most productive and cheapest, but is not designed for the manufacture of parts of complex configuration.
Picture : guillotine metal cutting
- Band saws are designed for cutting all kinds of metals and alloys. A method characterized by low waste. The edges of cuts are as flat as possible. There are restrictions on the size of blanks.
Photo : Metal cutting on a band saw
Metal is cut on special equipment using a solution (water abrasive sand), which is fed under high pressure through a narrow nozzle. Innovative technology designed for cutting metal up to 30 cm thick. The resulting parts do not require additional processing. In this case, the metal is not deformed, t. к. There is no thermal impact.
Photo : waterjet cutting of metal
This process is very expensive and not suitable for metals that are prone to corrosion.
Technologies of hot cutting
- Laser. Workpieces are processed on special machines. When a laser beam is applied, part of the metal evaporates. The remains of the molten material are blown out by the gas mixture.
Laser cutting produces any configuration of high-precision parts that do not require additional processing. However, the method has disadvantages:
- Metal thickness limitation. up to 20 mm thick workpieces can be processed on laser machines;
- Expensive. the of machines and their operation are kept at a high level;
- Restriction on types of metals. laser treatment is not suitable for stainless steel, aluminum and other alloys with high reflectivity.
- Gas. Workpieces are machined on special machines. The cutting technology is based on intense melting of the metal. It is produced by a directional flow of a gas-oxygen mixture.
Suitable for rough cutting of metals and alloys with low thermal conductivity. The high temperatures cause dross and slaggy deposits at the workpiece surface. The produced parts require further machining.
- Plasma cutting. Metal is cut with a high-pressure gas mixture. As a result, the material melts and burns out, and the residue and scale are completely blown away.
Photo : plasma cutting metal
Plasma cutting has the following advantages
- Cost-effectiveness. the amount of waste tends to a minimum, the resulting parts do not require additional processing;
- Productivity. plasma cutting is 4, 8 and 10 times faster than laser, waterjet and mechanical cutting, respectively;
- versatility. the technology is suitable for processing of any conductive metal with thickness from 1 mm to 15 cm.
Plasma cutting is used in both mass and individual production.
Particulars of sheet metal cutting
The basis of corrugated sheeting is thin sheet steel 0.3-1.2 mm thick. To prevent material from rusting and serving for a long time, it is covered on both sides with a thin layer of zinc alloy. For the decorative component, there are layers of special primer and powder coating, which also extend the life of the sheets.
During the installation work, the profiled sheeting is cut. The result is destruction of protective layers. That is why the most gentle tools are used for cutting, and edges are treated with corrosion preventing agents.
Edge protection from corrosion
There are special paints in spray cans, which are applied by spraying on the work surface. They are sold in the same colors as trapezoidal sheet. Another option. anti-corrosion mastic. In any case, it is necessary to read the instructions to find out whether it is necessary and what kind of primer before finishing should be applied to the damaged edge.
Choice of cutting tool
The main three criteria for choosing the optimal tool for cutting profiled sheeting are the permissibility of work with thin sheet metal, sparing and accurate cutting, convenience of the task. These parameters correspond to scissors, hacksaws, their electric counterparts and machinery with interchangeable discs. Let’s consider in detail the peculiarities of working with each of the options.
Hand scissors for metal for cutting profiled sheet is more convenient to use in the case of cutting a small number of workpieces and the formation of curved edges. Masters recommend choosing slotted samples from this category. Here The cutting part of the tool is represented by a rectangular plate (it is also the supporting part) and a movable sharpened head entering the groove of the plate. Sheet metal thickness for cutting can be up to 2.5 mm.
Another solution. it’s cutting or notching scissors for corrugated sheeting as an attachment to a drill or an electric screwdriver. There is a mechanism that converts the rotation of the chuck into reciprocating motion of the cutting elements of the device. They can be used to cut both steel workpieces and plastic and polycarbonate. Edges are obtained equally accurate regardless of the curvature of the planned line.
The third option scissors for cutting corrugated board. an electric tool. Externally, the technique is similar to an angle grinder. The working part is designed similarly to the drill bit described above. It also has a static part and a movable part. Only there are models, which during cutting act on the metal with one or two sides (as a cutter or hand scissors respectively). In the case of the first, there is one disadvantage. the edges of the blank sheet are slightly bent.
Manual hacksaw on metal despite the difficulty masters often prefer other tools than you can saw profiled sheet. This is justified by the accurate and precise results, the lack of restrictions on the thickness of the blade, safety against the background of electric analogues. The disadvantages include the difficulty of shaping curved edges.
Of alternative tools with power from the network or batteries for cutting corrugated board can be used jigsaw or saber saw. Only in the case of the first ones, the height of the wave on the workpieces should be limited to 20-25 mm to avoid the formation of a torn edge. The latter are equipped with a relatively smaller support plate, so there is no dependence on the relief of the sheet. But in each case, the speed of the saw blade movement must be adjusted in a smaller direction, so that the paint along the cutting line does not burn off.
Of this group of electric tools for cutting corrugated sheeting, two options are considered: an angle grinder or a manual circular saw. Experts do not agree on the former. Consider in more detail the relevance of using both variants.
Angle grinder due to its versatility and efficiency is available in almost every home workshop. As a tool for cutting corrugated sheeting, it can also be used. However, many craftsmen and manufacturers of metal sheets do not recommend this approach. This is justified by the accompanying damage to the paint and the protective coating of the material. The reasons lie in the high speed of rotation of the disc and flying red-hot sparks. burrs also form on the edges.
Despite the likelihood of negative consequences, the angle grinder is still often used in the installation of profiled steel sheets. In that case, you must properly pick up for angle grinder disk for cutting corrugated board. Here masters recommend paying attention to the following points:
- during the work with the abrasive wheel a large number of sparks are formed, the width of the damaged paint reaches 5 mm from the edge;
- There is a special cutting disc for cutting corrugated board with a thickness of 1-1.6 mm with small carbide teeth, which causes less damage to the material, but eliminates it completely;
- in order not to damage all the sheets necessary for cutting, it is possible to prepare several samples in one run with a diamond disk (there can be up to 10 pieces in a pack), but it is necessary to exclude the displacement of the blades;
- when using any tooling the edges of the cutting line are formed jagged;
- Choosing a cutting disc is important to consider the depth of the wave on the corrugated board to make a cut in its lower points and not to turn the sheets to do so.
Another disc tool than to cut profiled sheeting with high performance. a hand-held circular saw. It differs from the angle grinder less speed of the wheel (almost 2 times) and the presence of a wide support platform. The cutting disc is also selected as a specialized metal disc, thin, with fine teeth of carbide metal. And the disadvantages regarding damage to the protective coating on the sheets are the same.
Cold types of metal cutting
Cutting metal mechanically is a complex process, because metal products have high strength and hardness. The cold types of metal cutting include:
Cutting with a guillotine.
This method of cutting uses special mechanical tools. scissors and knives for metal. The workpiece is installed on the work table and secured with a clamping beam. Then a special blade is used to cut. The result is a perfectly straight edge, with no extra edges, burrs and nicks. Cutting material across the entire width of the sheet at once, so the curvature of the cut is zero.
The following types of guillotines are currently used for cutting metal:
They do not differ from each other in the principle of operation, but the last three types are complemented by electronics, ensuring accuracy and safety of cutting. There are also machines that can cut metal not only crosswise, but also lengthwise. The guillotine type of machining is most often used for blank work.
Disadvantages of this method:
- May not be used for all types of metals and has a limit on the thickness of the workpiece. For example, hydraulic machines are designed for metal thicknesses up to 6 mm.
- The resulting cut blanks often do not match the required dimensions, since the accuracy of machining depends on the skill of the operator.
- It is not possible to carry out shape cutting.
- Cutting copper by laser: advantages and disadvantages of the technology
- Types of metal cutting: industrial application
- Metalworking according to drawings: convenient and profitable
Band saw cutting.
Currently, this type of metal cutting is very popular because of the low cost of the equipment, good productivity and easy maintenance. The cutting tool is a band saw stretched on pulleys.
Modern band saws (LPS) are supplemented by a variety of equipment and electronics, thanks to which the unit is easily built into a particular production line for trimmer. The cutting speed of such a machine is on average about 100 mm/minute and higher.
The method of cutting on the LPS makes it possible to achieve exact compliance with the specified parameters, and the place of the cut does not need additional processing. The method is good for high-precision products and parts with a smooth surface. LPS is suitable for any metal, and the cutting width is only 1.5 mm.
When this type of metal cutting it is important to observe a number of conditions:
- accurate selection of the pitch of the cutting blade teeth in accordance with the cross-section of the profile to be sawn with the help of special tables;
- feed rate;
- cutting speed.
The LPS allows you to cut metal workpieces at an angle, which is a big advantage over the guillotine.
The disadvantages of this type of metal cutting include the inability to obtain a shaped cut and the limitation of the size of blanks depending on the capabilities of the machine.
Cutting metal with a circular saw and “angle grinder”.
A circular saw makes precise, good quality cuts. This tool allows you to control the angle of the cut.
The disadvantages of this type of cutting include a large amount of waste, low speed and shallow cutting depth.
For cutting rolled sections, an angle grinder can be used. There is no dross or oxide residue where the cut is made, so there is little waste.
But the low productivity of this type of metal cutting is its main disadvantage compared to other methods.
How to hold an angle grinder correctly
Many people have an angle grinder, but most people don’t know how to use it properly and how to hold it. This leads not only to defective work, but also to serious injury. The angle grinder is a fairly dangerous power tool. The circle must be installed with the pattern upwards and clamped with a special nut.
The person with the leading right hand holds the angle grinder by the handle with the right hand. In this case, the wheel should be located on the left side of the machine, and the safety guard should cover it from above. The rotation is such that sparks fly at the worker while cutting. If the angle grinder’s wheel jams and the angle grinder breaks free from his hands, it will not go to the cutter, but to the opposite side.
The left hand holds the machine by the handle, which is screwed into the threaded hole on the housing. There are several for special use cases, but the correct position of the handle is only the top one.
This machine position requires the use of protective equipment. To protect the eyes and the exposed part of the face are safety glasses, or better yet, a face mask. To protect the exposed parts of the body from sparks and small splinters while cutting, a suit of thick material should be worn.
How to break a rail with a sledgehammer?
Drills, cutters, grinding discs and knives are used as the basic tools for cutting metal. This technique helps shape, remove excess material, polish, and size the square.
How to cut a metal angle?
If you need to cut an angle at 45 degrees, you need to use a protractor. Often it is not handy, in which case, along the edge of the angle measure the width of the angle and run a line for the trimmer from this point to the intersection of the shelves at the point of cut. Once the lines are drawn, you need only cut a square corner along those lines.
A powerful and rugged cutting tool. In essence, it is an electric hacksaw with reciprocating motion of the blade. Allows you to saw wood, metal, plastic, brick, and also to penetrate into hard-to-reach places.
How to cut a metal pipe?
The angle grinder is probably the most productive tool today for non-professional metal cutting. It makes it relatively easy to cut pipes, rods, angles and (with practice) even metal sheets.
SABEL SAW A powerful and reliable cutting tool. In fact, is an electric hacksaw with reciprocating motion of the blade. Allows to saw wood, metal, plastic, brick, and also to penetrate into hard-to-reach places.
What disc to cut metal with an angle grinder?
angle grinders are usually used to cut metals, that’s why abrasive metal cutting discs are most common. Their thickness is from 1 to 3 mm. The thinner the disc, the greater its runout and the greater the potential for misalignment. discs less than 1.5 mm thick are only suitable for cutting body steel and tinplate.
Metal cutting angle grinder (angle grinder, angle grinder) is the easiest way to process various solid materials, including metal workpieces. This tool is used for deburring and cutting fittings, round bars, pipes and profiles of various kinds.
How to cut metal with an oxypropane torch
Metal cutting is required to dismantle steel structures, cut any type of rolled products before machining or welding. And if the sheet or profile of small thickness can be cut with a mechanical tool (with manual, electric or hydraulic drive). Then to work with metal workpieces of great thickness you need a gas cutter, or in professional slang. an autogenous. In this article, the master plumber will tell you how to cut metal with an oxygen-propane torch.
Regardless of the size of the auto-gen and the type of heating gas mixture the cutting occurs due to the combustion of metal in a jet of pure oxygen blown through the nozzle of the head into the work area.
Take note! The basic and fundamental condition of gas cutting is that the burning temperature must be lower than the melting temperature. Otherwise the metal, not having had time to start burning, will melt and flow away. Low carbon steels meet this condition, but non-ferrous metals and cast iron do not
Most alloyed steels are also not amenable to gas cutting. there are restrictions on the maximum allowable doses of alloying elements, carbon and impurities, above which the process of burning of the metal in oxygen becomes unstable, or generally interrupted.The cutting process itself can be divided into two phases:
- Heating a limited area of the part to a temperature at which the metal begins to burn. And in order to obtain a plume of heating flame, some of the technical oxygen in a certain proportion is mixed with combustible gas.
- Combustion (oxidation) of heated metal in the oxygen jet and removal of combustion products from the cutting zone.
If we consider the classification of hand torches only, the following attributes are of fundamental importance:
- Type of fuel, power and method of gas mixture production for heating flame;
- Classification by type of combustible gas: acetylene, propane-butane, methane, universal, MAF;
Note! kerosene torches and gasoline torches, though they have the same purpose, are liquid fuel torches
- According to power: small (cutting metal of thickness from 3 to 100 mm). marking P1, medium (up to 200 mm). P2, high (up to 300 mm). P3. There are samples with increased cutting thickness. up to 500 mm.
- By the way fuel gas is received: injector and non-injector.
And if the first feature affects only the temperature of the heating flame, and power. the maximum thickness of the metal, the third feature is determined by the design of the torch.
The injector, or twin-tube, gas torch is the most common type of design. Technical oxygen in the torch is separated into two streams.
Part of the flow moves into the head of the tip through the upper tube and out through the center nozzle of the inner mouthpiece at high velocity. This part of the design is responsible for the cutting phase of the process. Control valve or lever valve is moved outside the body.
Another part flows into the injector. The principle of operation is that the injected gas (oxygen), coming out into the mixing chamber at high pressure and high speed, creates a rarefaction zone there and draws flammable (ejected) gas through peripheral holes. Due to the mixing, the velocities are equalized and a gas mixture with a velocity lower than that of the injected oxygen, but higher than that of the ejected combustible gas is formed at the outlet of the chamber.Then the mixture of gases moves along the lower tube into the head of the tip, comes out through the nozzles between the inner and outer mouthpiece, and forms a plume of heating flame. Each channel has its own valve on the body that regulates the flow of oxygen and combustible gas into the injector.
Without injection, or a three-pipe torch has a more complicated design. both oxygen and gas flows to the head through separate tubes.
How to cut profiled sheeting. so as not to spoil the material
Corrugated sheeting is a construction material used for roofing, facades, fences, etc. п. Its main advantage is simple handling. Since the profiled sheet has a small weight and thickness, the fitting is carried out directly on the site. To cut corrugated sheet enough to choose a simple hand tools and know the features of the technology. In this article, the master plumber will tell you how to properly make a cut profiled sheeting, what tools are used for this and what to process the cut to avoid corrosion.
Decking is a tin plate with a specific profile. Peculiarities of the cutting process are due to the presence of a special coating, which must not be damaged during cutting.
Protective polymer coating of corrugated board is not heat-resistant, that is, it does not withstand high-temperature exposure, and therefore preferably cold cutting methods. Do not use high-temperature methods of cutting (gas cutting), because the coating of the sheet immediately spoiled, in spite of the original factory methods of protection.
Among the common tools suitable for the operation:
- angle grinder, angle grinder;
- Electric hacksaw for metal;
- An electric screwdriver or drill bit;
- Metal scissors and electric scissors;
- Jigsaw. manual or electric;
- Electric circular saw.
The electric angle grinder is often used in construction because it can cut or grind any metal as quickly as possible. The device is also quite easy to use, and the speed of processing the surfaces is its main advantage.
But it is worth noting that when cutting a profile with an angle grinder, experts highlight the many disadvantages of using the tool.
- The red-hot metal particles in the process of work spoil the coating, burning it. If after cutting the material is not processed protective coating, then these places are formed corrosion.
- After processing corrugated board remains uneven edges, so you will have to additionally remove burrs from the surface.
To avoid such difficulties, you need to select special discs for cutting corrugated board and timely cover the sheet to size with protective paints.
To properly cut the profiled sheeting, you must pick up a disc that best preserves the protective properties of coating and will not spoil the overall appearance of the building material.
As already mentioned, an angle grinder with an ordinary abrasive and extremely coarse wheel can not be used to cut profiled sheeting, as it severely spoils the coating formed in the process of work sparks, which will certainly lead to the emergence of rust.
Therefore, you can use this tool, if you buy a specially adapted disc for cutting corrugated board. It is a very thin working circle (its thickness is less than 1.6 mm). The teeth must be made of carbide materials.
Please note! After cutting the material must be covered with a special protective paint to avoid corrosion
Some home craftsmen, in order to save time, prefer to cut a whole bunch of profiled sheeting with an angle grinder, putting a diamond disc on the tool. But experts do not recommend doing such things, because there is a risk of ruining the metal at the slightest displacement of the sheets.
- You can not avoid the formation of jagged edges (you will need additional alignment or cover the “sloppy side” of the corrugated board with another sheet).
- Strong noise from the angle grinder.
- Even with the right cutting wheel, the protective surface will be damaged by sparks.
How to cut metal with an angle grinder
Here is how to correctly cut sheet metal and other shapes with an angle grinder. There are a few basic recommendations.
- Watch the wear of the cutting part. The diameter of the disk depends on how deeply it will go into the workpiece. If the grinding wheel is worn out, replace it in time.
- Since the rotational axis gets considerably hot at high speeds, periodically moisten it with water. The cutting tool achieves better performance after cooling.
- What speed to cut metal with an angle grinder depends on the stated performance of the tool. You should not run it at maximum speed, because this leads to quick wear and tear. The optimum setting is about one-third of the limits.
- Hold the angle grinder when cutting metal, so that the disc goes perpendicular to the workpiece. Do not apply pressure to the body. the movement should be gentle.
Recommendations of experts on some types of work
Below we will tell you how to work with an angle grinder on various metal products.
Sharpening the chain of a chainsaw
Picture 2: sharpening chainsaw chain with angle grinder
The chain is sharpened on the chain saw arm. Use a 2.5 mm thick sharpening disc for the work. It is necessary to mark the first tooth that you will work. With competent action, you can renew the chain 4-7 times before it finally fails.
Start cutting thick metal with the angle grinder from the edges. If you start in the middle, the disk may jam and bend. During processing, apply force to the lower part of the cutter, which ensures the efficiency of the cut.
Picture 4: cutting corners with an angle grinder
You can use withered discs or small-diameter tools for cutting metal angles. It is important to remember that the work is staged: first they cut one part of the molding, then the second.
Sharpening a circular saw wheel
Picture 5: Grinding circular saw blade with angle grinder
Start by securing the angle grinder with clamps, leaving the rotating part of the tool accessible. Then bring the saw blade close to the sharpening block, but do not force it. The wheel must run tangentially along the workpiece. Keep a close eye on the sharpening plane as you work.
Polishing is a complete finishing operation on the workpiece. Eliminate minor defects such as scratches, chipping, and scrapes. The surface gets a refined shine, and the product gets a marketable look.
Cutters with interchangeable inserts. it is a compound metal-cutting tool, which contains removable working components, fixed on the body. The product is used to form grooves, inclined surfaces and ledges. They are used to prepare holes and create complex technological cutouts.
Grooving and shoulder milling involves complex operations on several surfaces at the same time. The operations are carried out with the use of profile milling cutters, provide preparation of technological protrusions and openings for subsequent connection of parts.
Cutter wear is a complex phenomenon that results from tool use. As a result of wear the sharpness of cutting edges decreases, the weight, geometry and mechanical stability of the product changes.
Calculation of cutting modes is carried out for mechanized and manual metal processing. According to the results of the calculations, the equipment is selected, the optimal way of carrying out the work and the amount of production costs are determined.