Lever scissors cut sheet metal, tin, cut aluminum profiles and wire. The stores offer a variety of models from different manufacturers of any price categories. Nevertheless, there are craftsmen who make this useful and simple tool with their own hands.

Lever shear device

lever scissors Corvette

The work of manual scissors for metal is based on the principle of a lever. The cutting of the material is carried out by two cutting surfaces about 20 cm long. In this case, one surface is rigidly fixed on the base, all the pressure force falls here. The movable cutter is also fixed to the bed. A slot is selected in the fixed blade to move the slider. It moves like a hinge in one plane.

The movable part of the scissors is attached to the slider. The working stroke of the slider is 15 - 32 mm. The movable panel is equipped with a long handle (about 50 cm), which increases the applied force by 20 or more times. Therefore, the metal is cut quite easily.

The body of the lever scissors is metal, the cutting surfaces are made of tool steel. On average, the instrument measures 56 x 18 x 45 cm and weighs about 30 kg. With the help of such equipment, you can cut a steel sheet with a thickness of 0.5 cm, aluminum or brass 0.6 mm, a profile with a section of 6x70 mm or a steel bar No. 13 with your own hands.

Types of lever scissors

The designs of lever cutters do not differ in variety, the main difference is in the type of drive:

manual - the most primitive device, by acting on the lever, the cutting blade is set in motion;
electric - work very quickly, differ high performance. Cutting metal on such equipment does not require any effort from the worker;
hydraulic - powerful, set in motion by a hydraulic drive. Widely used when high effort is required, for example, for cutting rebar or rod.

Hand scissors are divided depending on the purpose and design:

with straight blades - used only for cutting in a straight line;
with curved cutters - they cut out elements of complex shape and holes;
chair - used for cutting thick layers of paper;
finger - very thin incisors make holes;
lever - permanently mounted on a workbench.

The hand lever attachment only allows straight or straight cuts to be made.

In addition, the instruments differ in the length of the actuators:

with short blades for passing cutting;
with long cutting surfaces - for straight cutting;
combined scissors for all types, including contour.

cutting small parts lever scissors is impossible, they are convenient for large cutting or cutting work.

The tool can be stationary or portable. For work, both types are firmly fixed on a workbench or bed. This is the only way to accurately and safely cut metal. Clamps or bolts are used to secure portable scissors.

Rules for working on lever scissors

Before starting work, you must put on seals so as not to cut yourself with sharp edges. sheet metal!

fix firmly hand tool on the surface of the table;
place a sheet of metal perpendicular to the blades, holding it with your main hand (right for right-handed people);
gently and gently press the handle from top to bottom.

During work, you need to protect your legs from falling cut pieces of metal. Falls are especially dangerous, so you can not work barefoot or in open shoes. To install the scissors, choose only a solid, non-staggering base.

Homemade lever scissors

drawing of lever scissors: 1 - lower cheek, 2 - fixed blade, 3 - movable blade, 4 - upper base, 5 - screw for fixing the blade (2 pieces), 6 - bolts 4 pieces, 7 - knife lever, 8 - earring, 9 - lever, 10 - screw, 11 - tie bolt (2 pieces)

The bed of this model of hand scissors is assembled by hand from a pair of corners 7.5 x 7.5 x 0.8 cm. The fixed knife is attached to a horizontal base with a pair of screws. To align with the movable blade, the top of the base is cut off in half. Holes are made in the blades, countersunk for M8 screws 24 mm long.
On the upper base, with the help of hinged fasteners, the following are installed: on the lower surface there is a blade and a knife lever (dimensions 6.5 x 3 x 0.6 cm), on the upper part there is a lever (24.5 x 1.8 x 0.7 cm) and an earring (6 x 1.8 x 7 cm) for mobility.

Do-it-yourself blanks are cut with a hacksaw. The blades are machined from hardened steel, the sharpening angle is 30 degrees.

First, we collect all the details in finished machine, setting up. After we disassemble, we paint. Once the paint is dry, clean it up.

Since the presented design is quite small, it is mounted on a workbench in a vise. You can install the tool permanently on the workbench. To do this, the base is welded to the corner, which is attached to the workbench with screws. Spacers are used to adjust the blade ratio.

drawing of manual lever scissors for metal

This model of hand scissors is complemented by a detailed drawing. Cutting of metal is done with a pair of blades 10 cm long each. The movable blade is attached to the wings on the crank mechanism. The crank eccentricity is 16mm and gives a maximum amplitude of 3.2cm. We attach a handle 50 cm long to its tail.

It is recommended to make a stationary version of the scissors, which will securely attach to the working surface M10 bolts. For fasteners, paws with holes are provided. The body of lever hand scissors must be made of high-quality steel 45 or 40, and the blades of grades P18, P9 or U10.

The scissors made according to this drawing have been successfully working for more than 2 years, coping with a steel sheet up to 3.5 mm thick.

Video from detailed description drawings, design and manufacture of lever shears for metal:

DIY roller knife

Cutting metal at home is a rather tedious process. And its quality often leaves much to be desired, forcing additional processing of the resulting faces. To correct the situation in many ways allows the use of special devices, including those made by hand. We will talk about one of these devices, namely the roller knife, today.

Roller knives for metal

The roller knife is gaining more and more demand and popularity today. This is due not only to the high productivity of such a device, but also to its rather simple device. The principle of operation of the mechanism is simple - two cutting disc-rollers rotate in different directions, pressing into the surface of the metal and thus cutting it. The friction between the metal and the knives ensures that the workpiece moves smoothly along the tool.

In the vast majority of cases, roller blades for cutting sheet metal include two rotating rollers - upper and lower. Depending on the variation of the cutting element used, such tools can be classified as follows:

Parallel position knives - used to cut metal into strips, while providing a very acceptable quality;
Edges with one inclined - this group allows not only longitudinal cutting of the material, but also cutting out ring and round blanks;
Knives with multiple bevels - similar devices make it possible to carry out an effective cut of workpieces of a round, curved or annular formation with a small radius.

It is worth noting that all of the above variations do an excellent job with cutting sheet steel, while the cut edges do not require additional attention and subsequent processing.

Homemade roller knives

With all its undoubted advantages, even the most simple model roller knife has a very decent cost. This is the reason for the inappropriateness of its acquisition for one-time work or periodic use. However, the optimal solution from a financial point of view still exists - it is quite possible to make a roller knife with your own hands at home.

The design of such a device can be very different. The most common variations are presented below (photo, photo 2). But in any case, the main part remains unchanged - the cutting knife. It should be made from the most durable and reliable steel alloy, the strength indicators of which must necessarily exceed those of the material being cut. If this condition is not met, the cut quality will be low, which will require additional processing of the cut edges.

Practice shows that the working life of factory-made knives is about 25 km of sheet steel, provided that its thickness is 0.5 mm. With a greater thickness, the resource will be correspondingly lower. However, the tool can be sharpened without problems and continue its effective functioning.

Speaking of resources homemade knives, then it is directly dependent on the material from which the cutting parts of the unit are made.

What can a knife be made of?

The options can be very different, here you need to pay attention to what exactly is planned to be cut. So, if it is not the most durable sheet steel in its structure, including aluminum, galvanized metal and other similar materials, the most common bearings will be a suitable solution. True, for this you will have to carry out a preliminary sharpening of their ends.

For cutting, one of the rollers, the one that will play the role of a drive one, is installed on the handle, due to which the knife will be pressed to the metal. Notice what larger diameter bearings, the faster the material can be cut.

In order for the cutting process to take place with maximum comfort and accuracy, the device can be additionally equipped with guides - this will not be particularly difficult, but in the future it is guaranteed to do good service.

The resulting tool is quite versatile and can be used in combination with a wide variety of metalworking equipment, including sheet bending machines, which you can also make yourself at home.

How to make a guillotine for cutting metal with your own hands?

In a home workshop or a small business for the manufacture of sheet metal products, sheet metal shears, or easier - a guillotine, will never be superfluous. The drive version can be installed, for example, in a garage, and a manual guillotine does not take up much space at all. If there is enough a large number manufacturing options (in drawings, videos or descriptions), as well as some adapted nodes from some kind of decommissioned equipment, making homemade metal shears is an affordable reality.

Homemade manual guillotine

The work of the most simple scissors for metal

The principle of cutting with guillotine (sheet) shears is that the knife beam of the device, to which the movable part of the tool is attached, must have an angle of 1.5 ... 3 ° along the working end, as a result of which metal cutting occurs non-simultaneously across the entire width. This reduces the cutting force, but requires a technique that would compensate for the shift of sheet metal (tin, thick cardboard, etc.) during cutting. Thus, a reliable clamp is required.

The main components of the saber guillotine

To drive a homemade guillotine, you can use a low-power electric motor, since the energy intensity of the process is low. But according to the results of calculating the maximum cutting force, a manual drive is often enough, for example, lever type(V homemade devices often offered). It will also require reliable guidance of moving parts during the cutting process, as well as a rigid supporting surface of the bed. In this case, the details of the homemade guillotine and the product itself will not be elastically deformed.

The drawings usually indicate the limits of the thickness and width of the sheet metal, or tin, for which the device is designed. If the whole process of obtaining sheet shears with your own hands is carried out independently, then the design begins with clarifying the power characteristics of cutting and choosing a mechanism scheme.

The initial data for choosing a design are:

type of material with which operations will be performed;
limiting dimensions of the sheet in terms of thickness, length and width;
separation accuracy;
limiting overall dimensions of scissors;
type of drive.

Mechanical guillotine shears

The manual device is the simplest in design. It includes:

support table on which the original workpiece will be located;
two or four racks that will provide strength and stability to the scissors;
a rotary axis with plain bearings (rolling bearings are unsuitable, since the gaps during the operation of such a guillotine will change significantly, which will quickly lead to jamming);
knife beam, which provides seats for fastening replaceable knives;
fixed knives that are mounted on the front end surface of the desktop;
a rotary type lever that will force the beam to move during cutting;
clamps for fixing metal.

Do-it-yourself production starts from the table. Its dimensions should be sufficient for convenient placement of the workpiece, taking into account the places for fixing clamps: there should be at least two of them, on each side of the sheet. The thickness must exclude deflection under the deformation force. The easiest way is to adapt a steel plate, which is installed with your own hands on the channels. The joints can be bolted flush with the top surface, or welding can also be used. The front end must be ground to ensure the evenness of the subsequent fit of the fixed knife to it.

The next step is to get support racks with your own hands. They must be made from a single profile. fit square pipes from high-quality medium carbon steel, or a channel. The section size can be easily calculated from the ultimate load on the racks, which is the sum of the own weight of the components of the manual guillotine shears for metal, and the cutting force P, kN.

The latter is calculated according to the dependence:

k is a coefficient that takes into account the possible unevenness of the working gap, blunting of the cutting edges, the quality of the material being cut, etc. Usually k = 1.05…1.3;

B - the largest width of the metal sheet, mm;

s is the maximum metal thickness, mm;

σ cf is the shear strength of the material, MPa.

For the most commonly used household materials given parameter is, MPa:

for mild steel - 280 ... 2
for medium carbon steel - 300 ... 400;
for high carbon and of stainless steel – 400…500;
for tin, aluminum - 65 ... 80;
for copper, brass - 180 ... 200.

When assembling the racks with your own hands, it is imperative to maintain the parallelism of the supporting surfaces and their perpendicularity to the axis of rotation of the knife beam. For these purposes it is better to use laser level. The floor at the installation site of the scissors must be made even and durable. Do-it-yourself installation of equipment on compacted soil, laminate and other options for coating concrete with polymers is not allowed.

A particularly crucial moment is the manufacture of a knife beam with your own hands: its profile must be made such that during the turning process the movable knives gradually come into contact with the metal being cut. There are two options for this:

profiling along the contour of the saber, with a gradual increase in the radius of curvature as it approaches the lever handle;
a pyramidal profile with a bevel angle of not more than 5 ... 60 (at a larger angle, the metal will begin to deform and bend in the direction of the axis of rotation).

The saber profile is more difficult to make, but it provides a smoother penetration into the metal being cut.

For a better direction of the case, it is placed either in a special groove on the table, or - with increased deformation forces - they design special guides that are attached to the racks with their own hands.

Manual homemade guillotine

It is better to make the axis of rotation from high-quality carbon steel, and then harden it to a hardness of at least 42 ... 45 HRC. Bearing bushings are made of OF10-1 bronze, which has good wear resistance.

For the manufacture of tools, tool steels U10 or U12 are used, hardened to a hardness of 48 ... 54 HRC. Hardened knives are carefully ground with their own hands, after which they are sharpened at an angle of 85 ... 90 °. The values of the gap between the knives are taken within 3 ... 6% of the thickness.

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Simple and easy-to-use scissors for cutting thin sheet metal are easy to make in any workshop. They can cut strips of the same width without marking the cut line, identical blanks at a right angle, cut the shelves of the squares to a given width. Performing these operations simple scissors for metal requires marking, takes a lot of time, and the cut line is not always even, especially if the workpiece is long.

The frame of the scissors is made of two squares with a section of 75x75 mm, a length of 200 mm, fastened together with M6 screws.
Two identical knives 120 mm long are made from old flat files with a section of 8x35 mm or from U7A or U8A tool steel.
The fixed knife is attached to the frame, the movable knife is fixed to the lever with screws No. 6 flush.
Files should be annealed at a temperature of 750-800 ° to a dark cherry-red color and slowly cooled in air. Then cut to length, and drill two holes in each of them for fastening. After the holes are drilled, a notch on the grindstone is ground on the adjacent planes of the files. Then the knives are heated to a temperature of 830-900 ° (to a light red color) and quickly cooled in water or mineral oil. So that they do not warp during hardening, they should be lowered vertically into the water. After hardening, the cutting edges of the knives are sharpened and filled on a bar. The lifting angle of the lever is adjusted by the limiter so that the planes of the knives do not come out of contact.

1 - base; 2 - screws for fastening the bed to the base: 3 - screws connecting the squares of the bed; 4 - screws for fastening Burdens; 5 - nuts for fastening the lever; 6 - washer; 7 - gasket; 8 - limiter screw; 9 - limiter; 10 - guide ruler; 11 - retractable bar; 12 - clamping screw of the bar; 13 - holes for screws fastening the corner plate; 14 - guide line stopper; 15 - knives; 16 - squares of the bed; 17 - lever; 18 - screws for fastening the corner cover; 19 - corner plate for fastening the cut square.

The lever is made of steel 8-10 mm thick, 30 mm wide. It must be rigid enough to ensure a snug fit of the working planes of the knives to each other.
A guide ruler is installed on the frame, made of steel 6-8 mm thick. It moves in the grooves parallel to the plane of the knives.
The working planes of the ruler are extended or filed strictly under the ruler and square. The location of the ruler on the bed is fixed by two M6 lamb stoppers. In the lower plane of the ruler, a groove is sawn or milled at a right angle to the leading edge, in which a retractable bar with a section of 20x2 mm moves, which allows cutting blanks at an angle of 90 °. The position of the bar is fixed with an M5 clamping screw with a washer.
So that when cutting the allowance of shelves on the lever scissors, the square does not bend, a removable clamping corner plate is made of sheet steel with a thickness of 0.8-1 mm. It has a cross section of a non-equilateral square. One shelf should be 1-1.2 mm less than the thickness of the guide ruler on which the square is installed; the other is 15 mm wide. In the larger shelf of the corner plate, the holes for the screws are sawn with a round file into elliptical ones.
If, when cutting thin material, it bends, then the planes of the knives are poorly fitted. If the flange width of the square to be cut is not the same, the corner trim is installed with a large gap.
Depending on the quality of the knives, lever shears can cut sheet material up to 1 mm thick. At the same time, it is not recommended to cut steel or other thick wire so that the scissor blades do not become serrated.
Finished scissors color oil paint, except for working planes, which are lubricated with machine oil.
The bed is attached to the desktop with screws, bolts or a clamp. The scissors will be portable if they are fixed on a base made of a 30 mm thick board measuring 500x200 mm.

How to do homemade guillotine for metal?

The presented do-it-yourself guillotine works on the principle of lever scissors, designed for cutting sheet metal with a thickness of not more than 3 mm.

It is made from improvised means, in particular from an old file and scraps of metal structures.

The manufacture of a guillotine consists of several stages. First, it is imperative to carry out drawing work in order to accurately determine the dimensions of the product. Applied scale is 1:1.

It is also recommended to draw a kinematic diagram with which it will be possible to determine the dynamic parameters of moving parts without taking into account the acting forces.

Drawings of parts printed on paper are printed on a printer and then cut out. The model of the machine is assembled from the cut out parts. This is done in order to verify the correctness of the calculations made and the exact correspondence of the dimensions to each individual component in the context of the functioning of the entire mechanism as a whole.

It is very important to determine the cut level indicator. It will be located at the intersection of the movable blade with the base, which is conventionally indicated by a line drawn in pencil.

The next step is the selection of pieces of scrap metal that are suitable in size, followed by the template application of the contours of future components on them. It is at this moment that paper clippings from under the animation turn into an important stencil.

In this case, the trimmings of a corner and a piece of iron sheet lying around acted as a blank. And as a result of the intensive work of the grinder, either cutting torch the main parts of metal scissors were obtained. These are two ears, a handle, a body holder and the body itself.

A base of two scalded corners is attached to the body of the guillotine. Their thickness is 50 mm. Pay attention to the accounted space for visits in the mode: "leaf up", "leaf down". There is also free space for a file. In this case, it is necessary to proceed from the parameters of its thickness plus the required clearance.

Then, with the help of mounting bolts, the process of sequential assembly takes place. The handle is attached to the main structure of the scissors by means of two ears. After that, one end of the body holder is screwed to it. The second is joined to the handle.

As a result, it should turn out, here is such an instance. Provided that no errors were made in the previous stages, the moment of complete cutting should occur when the handle reaches a horizontal position. The minimum movement of the arm against the background of the maximum travel along the radius must also be achieved.

The blank for two blades was an ordinary old, and therefore ground off, file. To begin with, it should be cut into two parts. Three holes are drilled in each of them for fastening. After that, the blade profile is formed and the edges are sharpened directly.

The images show the attachment points of two cutting knives. The movement of the upper knife must not be obstructed by other parts of the machine. It is important to bring the profile in such a way that, over the entire width of the cut, the interaction of the knives occurs at an angle of 6-8 degrees.

Ready-to-use homemade lever shears with clamps or specially for this drilled holes securely fixed on the work surface of the workbench.

Subject to the basic technological rules during the manufacture of the machine, it will certainly show very high efficiency. And it will easily cut both paper leaves and 3 mm iron.

Video: do-it-yourself manual guillotine for cutting metal.

Among all types of separating equipment designed for cutting metal, lever shears are considered the simplest and most compact. They can be manually operated or powered by an electric motor. The versatility of this type of forging and stamping equipment makes it possible to install such scissors in almost any household workshop, and even more so in small private enterprises working with bar or sheet metal.

Principle of operation and design features

Unlike sheet shears with an inclined knife (guillotine), the movement of the knife in lever shears most often occurs not along a translational, but along a rotational path. In addition, not a crank-slider, but a lever is used as the main actuator.

Lever scissors, assembled according to the scheme of a single-arm lever, have become most widespread. When cutting thin metal, with a thickness of not more than 0.7 ... 0.8 mm, manual metalwork scissors are used, and when thicker, chair scissors are used, the lever of which is much longer. In addition, the schemes of chair scissors provide for the possibility of embedding an intermediate gear. This increases the length of the trajectory of the movable knife, but reduces the resulting force, which is important if the unit has a manual drive.

The largest versions of the chair scissors allow cutting steel sheets with a thickness of up to 8 ... 10 mm, and long products with a diameter of not more than 22 mm.

Lever chair scissors with a manual drive are designed in such a way that the drive lever has the shape of a saber. This allows you to bring the trajectory of motion closer to the work of guillotine shears: the introduction of the moving part of the working tool into the metal being cut also occurs gradually. As a result, the current value of the cutting force is reduced. Non-driven (manual) chair-type scissors can cut steel up to 2 ... 2.5 mm thick.

The typical design of desktop lever scissors is a combination of the following units:

beds;
eccentric or screw clamps, by means of which the equipment can be permanently attached to the locksmith's workbench;
the lower support frame, on which the fixed part of the equipment is installed;
saber swivel lever with handle (for manual models). the movable part of the equipment is installed on it;
axles with plain bearings.

In the drive lever scissors, in addition to the above units, there is also an electric motor, a V-belt transmission, as well as a crank mechanism that converts the rotational movement of the motor shaft into the rocking movement of the lever. Sometimes such equipment is equipped with a switching mechanism (clutch and brake), and in this form they are not much different from stationary alligator-type scissors. Their only advantage in this case is the absence of a balancer that compensates for the inertia of massive parts.

Limitations of lever scissors and the possibility of overcoming them

The main disadvantage of lever shears that do not have a mechanical drive is the need to make very long movements in order to reduce the metal cutting force. In addition, at manual drive it is impossible to ensure the constancy of the cutting speed, which can degrade the quality of the metal separation surface. By extending the drive, one has to sacrifice the overall dimensions of the equipment. In addition, the lengthening of the shoulder always worsens the control over the quality of the clamping of the workpiece, and requires the use of more powerful clamps that keep the metal being cut from moving. At the same time, there is also no possibility for high-quality cutting of profiled products: bars, angles, etc.

These limitations are overcome by designs with a multi-link cutting mechanism, as well as by using various ways amplification without the participation of muscular strength. This does not require a mechanical drive.

Cutting rules

In the first case, predominantly kinematic schemes with two levers are used. To the main lever (each part of which is connected to the other part using a common axis), an additional one is added, and its connection with the main pair is achieved by the presence of a cylindrical rod with a rack and pinion drive.

The rack mechanism consists of the following parts:

intermediate lever;
return springs;
swivel brackets;
screw pair connecting the rail to the intermediate rod.

This method, although it provides a higher quality of metal cutting, but significantly complicates the scheme of lever scissors. It is very difficult to make such an option at home, in addition, the worker's effort will remain quite high.

If, instead of a rack and pinion, a mechanical amplifier is placed in the intermediate rod, then the resulting load will noticeably decrease. This kind of manual lever scissors includes, in addition to the main working elements, also:

cylindrical hollow rod;
amplifier with self-braking thread;
connecting rod;
spring-loaded latch;
counterweight.

The presence of a load gives the metal cutting process an impact character, due to which it is possible to increase the cutting energy and separate workpieces with a greater thickness or cross-sectional area. However, the shock nature of the load application tires the worker (especially during prolonged work), and the amplitude of the vibration of the device on the frame increases. To install such scissors, you will need a more reliable support and Smooth surface gender. Metal cutting performance will also decrease.

The three-tier scheme is considered the most modern. In this case, the required compromise between the applied force and the length of movement of the movable tool is achieved.

Three-link lever scissors

It has been established that the scheme, which will be described below, makes it possible to cut bars and sheets with a cross-sectional size of up to 10 mm, which in most cases is sufficient not only for their own needs, but also for the manufacture of steel products within a small business.

Such scissors consist of the following nodes:

Beds, for the manufacture of which you will need two equal-sized corners with a shelf thickness of at least 7 mm.
The lower support to which the working tool is attached.
Upper support, which is installed in seat, and has a bevel to reduce the gap between the knives at the start of cutting.
Cases, mounting holes for knives in which it is worth making a little oval shape to compensate for possible tool installation errors.
Earrings.
connecting axis.
Fasteners.

For the manufacture of all parts of the multi-link mechanism, medium alloy steel grade 35 or higher will be required.

The length of the support frame is determined by the maximum dimensions of the metal being cut: the size of the hand shears will be approximately twice the width of the workpiece. Nevertheless, the design turns out to be quite compact, and allows the use of conventional metalwork vise and an appropriately sized workbench for its installation.

The mounting scheme of the working tool is as follows. Fittings made of high-strength tool steel grades U10 or U12 are equipped with mounting holes with a countersunk conical part in order to flush fastening. The kit should include options for cutting profiled metal. To facilitate maintenance, the equipment should be made double-sided. Further, heat treatment is carried out to a hardness of at least 54 ... 56 HRC, and grinding is carried out in order to eliminate the probable warpage of the working canvas. The finished equipment is installed in the lower and upper landing parts, and they are fitted one after another so that the actual gap between the movable and fixed parts does not exceed 5 ... 8% of the thickness of the metal being cut.

Maintenance and operation

The main routine maintenance of the equipment consists in periodic sharpening of tooling (during the first operation, it is enough to simply turn the knives by 180 °). Sharpening can be carried out on grinder using a carborundum wheel, after which it is necessary to grind the resulting surface. After repeated regrinding, the stability of the gap must be maintained by installing gaskets made of steel. Their thickness is determined empirically.

Lever shears for metal serve as an improvised tool when cutting huge sheets of metal or cutting wire. What is the unusualness of such scissors for us, and where can we use them?

Purpose and device of scissors on the lever mechanism

During the production process, there is a constant need to divide whole parts of materials into smaller fragments. To facilitate the work, there are many devices and tools. Many of the appliances, originally invented for manufacturing purposes, have firmly entered our everyday life: an electric hair dryer (a reduced version of drying for molds), scissors, a microwave oven.

Most industrial tools remain part of the manufacturing process without making their way into our homes. K is typical professional look fixtures include desktop lever. This is a mechanical tool for cutting metal sheets, tin, as well as steel bars and wires from other types of metal. They also produce manual shears for metal (which are held in the hand when cutting) and electric ones. Let us consider in detail one of the types - scissors on a lever mechanism.

The device of lever scissors is quite intricate. As mentioned above, this mechanical tool works on the principle of a lever. The cutting process takes place with the help of two knives about a hundred millimeters long.. One knife is motionless, it is attached to a support, it is called a bed and takes on all the pressure that occurs during work. In most tools, moving parts move along the bed, in this tool the principle is the same. In the fixed part there is a groove along which the crosshead (or slider) moves. This is such a part that moves back and forth, like a hinge.

The other panel moves freely on the backstage, which is fed by a crosshead. The eccentricity (a number indicating the deviation of the conical section from the circle) of the slider is from 16 to 32 millimeters, with 32 millimeters being the maximum working stroke of the crosshead. At the end of the movable panel there is a handle 500 millimeters long. Using this pen allows you to multiply the applied force many times (more than 20), which makes it easier to cut the metal sheet. This is because the transmission force increases the pressure on the knives, so it is much easier to cut with such scissors.

Lever scissors - characteristics and types of tools

Now let's discuss the general specifications! dimensions this tool is standardly 560x175x460 millimeters (length, width, height). Weight, on average - 30 kilograms. Knives are made of high-quality tool steel, grade U8-U10 or P9, P18. The maximum thickness of the steel sheet that is recommended for processing is 5 millimeters, but the cross section steel profile- 70x6 millimeters (maximum). Above, in the description, it was emphasized that the scissors on the lever mechanism are also suitable for cutting bars. largest diameter steel bar - 13 millimeters, width - 300 millimeters.

This type of tool can perform two types of metal cutting: straight and through, but both types are only in a straight line. Bent cutting is not possible with this tool. Straight cutting is cutting through the material in one motion. And the passage is the separation of one part from the other sectionally, in several movements of the knives, according to the principle of classic scissors. On this basis, that is, according to the length of the blades, the tools also differ: with long blades - for a straight cut, and with short ones - for a through cut. There is also combined type scissors - for straight, continuous and contour cutting (cutting contours).

Thus, there are three types of lever scissors: straight, through, combined.

Next, consider the types of scissors according to the possibility of movement. Portable and stationary scissors are available. In both cases, the tool must be securely fixed to the work surface. This is a prerequisite for safety, and, in addition, prevents the curvature of the cut. To fix the portable model, you can use clamps - special clamps that are used to fasten something to a workbench or fasten materials together. The clamp has a screw that, by rotating, moves the clamp to the plate, firmly tightening the material between them. In the case when the lever tool is planned to be installed for permanent use, it is necessary to attach the legs to the working surface of the table with bolts. For bolts in the legs of the scissors there are special holes, it is better to use M10 bolts.

In cases where the thickness of the metal being processed is more than 0.5 millimeters, it is impossible to use manual metal shears, it is necessary to resort to the help of more powerful tool- lever scissors. Some masters call them "power" scissors, and, as the name implies, they are "stronger" than ordinary ones. You need to work in special protective gloves, because you can cut your hands with the sharp edges of the sheet.

Make sure the scissors are firmly screwed to the work surface. The metal sheet must be placed perpendicular to the knives, you need to hold the canvas with your leading hand, for right-handers - with the right, for left-handers, as you know - with the left. It has already been said about the thickness of the web, however, we recall that maximum size sheet steel - 4 mm, non-ferrous metals (brass, aluminum) - up to 6 mm. To carry out the operation successfully, you should install the sheet under the movable knife and smoothly, without jerking, lower the handle down.

The work of cutting metal requires strict adherence to safety regulations, even for experienced locksmiths. Most often, there are cases of hand cuts on the sharp edges of a metal sheet, so you need to wear protective gloves (we repeat this rule for reliability). Falls of material on the legs are also common, resulting in injuries to the feet and lower legs. Especially dangerous is the fall of the sheet with an edge, and not flat, in this case, cutting off part of the limb is possible.

The tool must be properly fixed, that is, it must be firmly screwed to the table, and the work table must not stagger. Scissors must be kept clean and in good condition. Work on a faulty or emergency tool is strictly prohibited for obvious reasons. In work, you need to be careful, report malfunctions and breakdowns of the tool, do not try to fix them yourself. It is necessary to report the incident to the mechanic for the repair and adjustment of this type of equipment.

Working on metal-cutting equipment is dangerous, on the one hand, because the scissor blades can injure the hands of the worker, on the other hand, working with sheet metal requires increased attention and responsibility, as it contains an additional risk of cuts to the arms, legs and torso. The worker's clothing should be semi-adjacent and not have protruding and hanging parts (long sleeves, scarves, etc.) in order to exclude cases of pinching parts of the clothing with the blades of the tool.

The presented do-it-yourself guillotine works on the principle of lever scissors, designed for cutting sheet metal with a thickness of not more than 3 mm.

It is made from improvised means, in particular from an old file and scraps of metal structures.

The manufacture of a guillotine consists of several stages. First, it is imperative to carry out drawing work in order to accurately determine the dimensions of the product. Applied scale is 1:1.

It is very important to determine the cut level indicator. It will be located at the intersection of the movable blade with the base, which is conventionally indicated by a line drawn in pencil.

The next step is the selection of pieces of scrap metal that are suitable in size, followed by the template application of the contours of future components on them. It is at this moment that paper clippings from under the animation turn into an important stencil.

In this case, the trimmings of a corner and a piece of iron sheet lying around acted as a blank. And as a result of intensive work by a grinder or a gas cutter, the main parts of metal scissors were obtained. These are two ears, a handle, a body holder and the body itself.

A base of two scalded corners is attached to the body of the guillotine. Their thickness is 50 mm. Pay attention to the accounted space for calls in the mode: “sheet up”, “sheet down”. There is also free space for a file. In this case, it is necessary to proceed from the parameters of its thickness plus the required clearance.

Then, with the help of mounting bolts, the process of sequential assembly takes place. The handle is attached to the main structure of the scissors by means of two ears. After that, one end of the body holder is screwed to it. The second is joined to the handle.

As a result, it should turn out, here is such an instance. Provided that no errors were made in the previous stages, the moment of complete cutting should occur when the handle reaches a horizontal position. The minimum movement of the arm against the background of the maximum travel along the radius must also be achieved.

The blank for two blades was an ordinary old, and therefore ground off, file. To begin with, it should be cut into two parts. Three holes are drilled in each of them for fastening. After that, the blade profile is formed and the edges are sharpened directly.

The images show the attachment points of two cutting knives. The movement of the upper knife must not be obstructed by other parts of the machine. It is important to bring the profile in such a way that, over the entire width of the cut, the interaction of the knives occurs at an angle of 6-8 degrees.

Ready-to-use homemade lever scissors are securely fixed to the working surface of the workbench with clamps or specially drilled holes for this purpose.

Subject to the basic technological rules during the manufacture of the machine, it will certainly show very high efficiency. And it will easily cut both paper leaves and 3 mm iron.

Video: do-it-yourself manual guillotine for cutting metal.

Lever shear device

The body of the lever scissors is metal, the cutting surfaces are made of tool steel. On average, the instrument measures 56 x 18 x 45 cm and weighs about 30 kg. With the help of such equipment, you can cut a steel sheet with a thickness of 0.5 cm, aluminum or brass 0.6 mm, a profile with a section of 6x70 mm or a steel bar No. 13 with your own hands.

Types of lever scissors

The designs of lever cutters do not differ in variety, the main difference is in the type of drive:

manual - the most primitive device, by acting on the lever, the cutting blade is set in motion;
electric - work very quickly, are characterized by high performance. Cutting metal on such equipment does not require any effort from the worker;
hydraulic - powerful, set in motion by a hydraulic drive. Widely used when high effort is required, for example, for cutting rebar or rod.

Hand scissors are divided depending on the purpose and design:

with straight blades - used only for cutting in a straight line;
with curved cutters - they cut out elements of complex shape and holes;
chair - used for cutting thick layers of paper;
finger - very thin incisors make holes;
lever - permanently mounted on a workbench.

The hand lever attachment only allows straight or straight cuts to be made.

In addition, the instruments differ in the length of the actuators:

with short blades for passing cutting;
with long cutting surfaces - for straight cutting;
combined scissors for all types, including contour.

Cutting small parts with lever scissors is impossible; they are convenient for large cutting or cutting work.

The tool can be stationary or portable. For work, both types are firmly fixed on a workbench or bed. This is the only way to accurately and safely cut metal. Clamps or bolts are used to secure portable scissors.

Rules for working on lever scissors

Before starting work, it is necessary to put on seals so as not to be cut by the sharp edges of the metal sheet!

Firmly fix the hand tool on the table surface;
place a sheet of metal perpendicular to the blades, holding it with your main hand (right for right-handed people);
gently and gently press the handle from top to bottom.

During work, you need to protect your legs from falling cut pieces of metal. Falls are especially dangerous, so you can not work barefoot or in open shoes. To install the scissors, choose only a solid, non-staggering base.

Homemade lever scissors

Option 1

The bed of this model of hand scissors is assembled by hand from a pair of corners 7.5 x 7.5 x 0.8 cm. The fixed knife is attached to a horizontal base with a pair of screws. To align with the movable blade, the top of the base is cut off in half. Holes are made in the blades, countersunk for M8 screws 24 mm long.
On the upper base, with the help of hinged fasteners, the following are installed: on the lower surface there is a blade and a knife lever (dimensions 6.5 x 3 x 0.6 cm), on the upper part there is a lever (24.5 x 1.8 x 0.7 cm) and an earring (6 x 1.8 x 7 cm) for mobility.

Do-it-yourself blanks are cut with a hacksaw. The blades are machined from hardened steel, the sharpening angle is 30 degrees.

First, we collect all the details in the finished machine, we are setting it up. After we disassemble, we paint. Once the paint is dry, clean it up.

Since the presented design is quite small, it is mounted on a workbench in a vise. You can install the tool permanently on the workbench. To do this, the base is welded to the corner, which is attached to the workbench with screws. Spacers are used to adjust the blade ratio.

Option 2

It is recommended to make a stationary version of the scissors, which will be securely attached once to the work surface with M10 bolts. For fasteners, paws with holes are provided. The body of lever hand scissors must be made of high-quality steel 45 or 40, and the blades of grades P18, P9 or U10.

The scissors made according to this drawing have been successfully working for more than 2 years, coping with a steel sheet up to 3.5 mm thick.

Video with a detailed description of the drawings, design and manufacture of lever shears for metal: