Do-it-yourself metal carving: technology, tools and types with photos

Artistic metal carving can give any object a beautiful and original look that attracts the attention of others. Surely you also have some item with an engraving applied to it - be it a lighter, a flask or a personalized pen. Name engravings have always been considered a sign of honor and wealth. Carving on pre-prepared metal will help you make your own artistic engraving a real value!

Perhaps you have wondered how a beautiful pattern is applied to a particular metal surface, or maybe you would like to master this fascinating craft yourself.

Firstly, most often, such work is performed individually, you become the owner of an exclusive item.

Secondly, the artistic engraving looks very beautiful.

Thirdly, you can do it yourself, at home. Engraving is the application (transfer) of a design onto a metal object.

How to make engraving on metal at home, what tool or machine is needed? What is the price of engraving tools? You will learn about this in our article.

Mechanics of the process: we study in detail

Try to imagine what happens to the metal of the workpiece at the beginning of the movement of the threading tool. Its first few turns converge into a cone, forming the lead-in part. A little force is enough for the sharp and hard teeth of a die or tap to press small grooves into the metal and become firmly fixed in it.

That's it, now the tool, as they say, has “taken a step” and will precisely follow the spiral of the thread, becoming stronger the more turns there are. But the fact is that metal cannot deform indefinitely. If the tool's teeth cut too deeply, they will push out excess material, creating chips. If you cut a hole with a regular hardened bolt, chips will clog the newly cut thread and the tool will have to be constantly unscrewed to clean the hole. The tap and die have special grooves for chip removal.

It is very important to understand that the teeth of the working part do not cut grooves in the metal. They push them, squeezing out the metal on both sides of them. Removal of excess is carried out by a notch between adjacent teeth: it gives the ductile metal a shape, and the remainder is thrown into the chip groove.

Drilling holes and pre-processing bars

From the last observation we can conclude that the outer diameter of the thread is slightly larger than the original diameter of the rod on which it is cut. Likewise, the axial distance between the tips of the internal threads will be slightly less than the hole.

If you look at any drawing depicting a metric thread, you can note a number of key dimensions:

Inner and outer diameter. These values change names depending on whether the thread is internal or external.
Thread pitch is the distance between the tops of adjacent teeth.
Shape and dimensions of the nominal profile, angles of inclination.

So: the diameter of the rod or thread hole is not equal to either the external or internal diameter of the thread. The easiest way to determine the hole size for an internal thread is to subtract the pitch distance from the outer diameter. For external threads, the same value must be added to the diameter of the rod.

However, real professionals always use tables of standard metric threads, where the recommended diameters also take into account the type of thread, the characteristics of metals and their alloys. So the main problem is finding the right rod or drill.

You set the basis for high-quality cutting at the stage of drilling or preparing the rod. The hole must be drilled strictly perpendicularly; among the ways to control the right angle, you can suggest combining the drill with the reflection in a placed mirror or placing a credit card nearby.

Rust should be removed from the rod and the side surface should be checked for evenness with a metal ruler. The best way to prepare the rod is to clamp it into the drill chuck and give the edge a good file. When rounding, it is allowed to grind the rod down a couple of tenths if this is necessary for alignment, which in practice is more important than the completeness of the cutting.

This is of little use when working with fixed rods. You have to select the thread diameter according to the diameter of the rod, choosing a value less than the recommended one. For a more convenient approach at the end, you need to remove the chamfer and perform the cutting especially carefully and accurately. Do not forget to generously apply machine oil to the area to be treated.

Cutting in several passes

Threads are usually made in several passes, using taps with different profile completeness. The main difficulty lies in the starting, setting pass. It is made with a tap with one thin groove on the shank. The tool must be inserted freely into the hole and, pressing it with a little force, turn it a couple of turns. In this case, the perpendicularity of the insertion is controlled by a credit card; small deviations of 5–7° are quite acceptable.

In 5–6 turns, the lead-in part is completely inserted into the hole and the tap confidently begins to move. Now the tool must be rotated without pressing force. It would be a mistake to correct minor deviations from perpendicularity at this stage - the tap is not to blame for this, it goes strictly along the hole. After every 1.5–2 feed turns, you need to unscrew the tool half a turn.

Areas of application for threaded connections

Threaded connections are used in industry and everyday life. With their help, a wide range of problems are solved:

connection of machine components and mechanisms;
installation of protective elements in the form of covers, threaded plugs, etc.;
installation of load-bearing components of metal structures;
formation of flange connections, which are in demand when laying pipelines;
installation of machines and other technological equipment.

Threaded connections are indispensable when assembling household appliances and measuring instruments. With their help, modernization and repair work of varying complexity is carried out.

According to their purpose, threads are divided into fastening, running, lifting, and also fastening with simultaneous sealing.

One-pass method

Single-start thread cutting is typical for mechanized devices. A single-cut tap has one wide or three thin grooves on the shank, or may have none at all. Other differences between machine taps: a short lead, a shank thinner than the nominal diameter, and a full thread profile.

You can cut through threads in thin (2–4 mm) sheet materials in one go. Machine taps are also very common for cutting blind holes. More precisely, they widen the trace from the leading part of taps #1 and #2, adding another 1.5–2 turns to the thread. If the third number has a long lead, you can cut it off completely and use this tap only for full threading in blind holes.

Single-start taps are no more difficult to work with than dies. There is difficulty in setting the correct position, but the technique is the same. By the way, most dies are also designed for single-pass operation.

What determines the price of custom sheet metal cutting?

The cost of cutting sheet metal is determined by a combination of interrelated factors, such as:

technology used;
equipment power;
brand, thickness of raw materials;
quality of finished products;
order quantity.

If during the work a large amount of raw materials will be used, the cost of the order can be reduced by reducing the value of the price of the accounting unit (kilogram, linear meter).

The cost of producing small batches is discussed with the customer individually in each specific case. The price of cutting sheet materials is not always calculated using the formula “unit cost multiplied by quantity”, since any order requires reconfiguration of working equipment.

Today, manufacturers use a variety of technologies for cutting sheet metal, but the main criteria for the customer are still the quality of work, production time, cost, and the availability of additional transportation services.

Tips and tricks

When cutting threads, never skimp on lubricant. The presence of oil on the working body helps prevent overheating and associated thread breaks. In addition, this way the friction force is greatly reduced and the tap can be felt perfectly with your hands. Add a couple of drops of oil every 4-5 turns.

Do not apply excessive pressure, threads up to 6 mm can be cut only with your fingers, up to 14 mm - with one hand. The tool may get stuck due to poor chip removal. In this case, it must be turned in both directions, gradually expanding the range of free play.

Don't use cheap, low-quality tools. Most cheap taps are very fragile. It's not a big deal to break one; it's much more of a hassle to have a piece in a hole that can't be re-drilled. In this case, the tap needs to be “warmed” a little with a hammer through the center punch, and then pulled back with thin-nose pliers or tweezers and gradually unscrewed. In sheet materials, it is easier to knock out a fragment and cut a thread of a larger diameter by pre-drilling a hole.

A tap is a tool that can be used to quickly and accurately cut a thread in a prepared hole. This is a rod divided into a working part and a shank. The shank is used for fixation in the driver or chuck of the machine. Chip removal is provided by longitudinal or helical grooves located on the cutting part. For the manufacture of this tool, carbon or high-speed steels are used. To cut internal threads efficiently, you need to know how to choose the right tap and prepare the hole.

Industrial types of sheet metal cutting

Metal processing can be carried out in different ways. The specifics of the work depend on the type of equipment used for cutting metal sheets.

At large industrial enterprises, waterjet or thermal cutting is most often used.

1. Heat treatment of sheet metal.

Thermal cutting involves separating metal sheets with a jet heated to extreme temperatures. This type of cutting is also called non-contact cutting, since the tool does not interact with the surface of the sheet material.

Types of thermal cutting: oxygen gas, laser, plasma.

Oxygen gas cutting of sheet metal.

Oxygen gas processing of sheet metal includes two stages:

A jet of flame coming out of the cutter is supplied to the starting point of the intended cutting line. Acetylene is used as the working gas.
After heating the material, the device supplies an oxygen flow, which easily cuts the softened metal. At the same time, oxides are removed.

In order for the cutting quality to be high, the distance between the cutter nozzle and the metal must be the same throughout the entire working process.

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Oxygen cutting is the most economical cutting method and is excellent for cutting low alloy steels. If all the nuances of the technology are observed and the craftsman has sufficient experience, the edge of the sheet metal after oxy-fuel cutting does not require additional processing.

The disadvantage of using this type of cutting is that it can only process metals with low thermal conductivity.

Plasma cutting of sheet metal.

Plasma cutting is considered a more universal method of processing sheet materials. The first equipment for this type of metal cutting appeared in the second half of the 20th century. The equipment was not only bulky, but also expensive, and therefore only large industrial enterprises could afford its acquisition and use. Over time, equipment has become more accessible, and the popularity of plasma cutting has grown exponentially.

VT-metall offers services:

In this case, metal processing is carried out using a high-speed plasma flow, the temperature of which can reach +30,000 °C. In this case, drops of molten metal formed as a result of melting are instantly blown away by a stream of compressed air. Compared to the previous type of cutting, plasma processing is highly productive, because the temperature of the oxygen gas flow is only +1,800 °C.

It is worth noting that the popularity of plasma cutting is explained not only by its high productivity, but also by a number of other important parameters. Thus, the work process does not require regular refilling of gas cylinders, additives for cutting valuable metals or increased attention to fire safety measures. To work with plasma equipment, you only need electricity and air, which allows you to draw objective conclusions about the simplicity, convenience and economy of the work process.

Plasma cutting of sheet metal can be used to process:

aluminum and alloys based on it up to 120 mm thick;
copper up to 80 mm thick;
alloy and carbon steels up to 50 mm thick;
cast iron up to 90 mm thick.

If the metal thickness exceeds 120 mm, it is more advisable to use oxy-fuel cutting.

When selecting the optimal equipment for metal processing, it is very important to take into account such properties as thickness and thermal conductivity. Here you need to remember one simple rule: the higher the thermal conductivity of the material being cut, the greater the heat removal and the smaller the possible thickness of the sheet being processed (for example, the thickness of a copper sheet should be less than a stainless steel sheet).

Types of instruments

The appropriate tool is selected depending on the characteristics of the material being processed, the required productivity and other parameters. Using different types of taps, you can cut metric or inch internal threads with a cylindrical or conical profile.

According to the method of conducting the process, models are distinguished:

Pass-through (universal) . Their working part consists of three zones. The first performs rough cutting, the second – intermediate, and the third – finishing.
Complete . To perform a full range of work, several tools are used - for roughing, intermediate and finishing cutting. The sets consist of three taps, less often of two (for roughing and finishing). For processing particularly strong metals, kits with 5 tools are used.

The tool is made of two types: for processing holes manually or using metal-cutting equipment.

Machine-manual . Has a square shank. Works complete with a holder with two handles - a knob.
Machine . Installed in the chuck of metalworking machines of various types.

Taps of different designs are used for cutting threads in blind and through holes:

For non-passable holes, use a complete tool without a conical tip. The work is usually done with a crank.
In through holes, threads are made using taps with a conical tip. Most often these are varieties of universal type tools.

The channels for removing chips have different shapes: straight, screw, shortened.

Chip channels of any shape are suitable for processing materials of low hardness. To tap threads in high-hardness materials, such as stainless and heat-resistant steels, use only a tool in which the cutting segments are staggered.

Read also: How to make conductive varnish with your own hands

Mechanical types of sheet metal cutting

Mechanical cutting of metal is a contact processing method in which the surface of the tool interacts with the material. The cutting element, as a rule, is also made of metal, but of higher hardness.

The group of devices for mechanical cutting of sheet metal includes scissors, a saw and cutters. A special type of mechanical processing of metal sheets is cutting. Impact cutting or chopping with a guillotine is usually used at the stage of creating workpieces.

Sheet metal machining can also be performed using the following equipment:

band saw machines (LPS);
guillotine;
disk machines;
lathes with cutters installed on them;
slitting units.

1. Cutting with a band saw.

It is advisable to use a band saw for processing long metal. This device is the main working element on a band saw machine (LSS). The operating principle of the saw is similar to that of a conventional hacksaw. The saw blade is enclosed in a large diameter band, one side of which has special teeth. Continuous movement of the belt is ensured by rotating pulleys connected to an electric motor. The average operating speed of the LPS is 100 mm/min. The working blade for such machines is usually made of carbon steel or a bimetallic alloy.

The advantages of using LPS include: accuracy, availability, favorable cost of equipment, the ability to perform both straight and angular cuts, efficiency (minimum amount of waste).

Modern machines for cutting sheet metal are equipped with electronics and additional elements, which allows them to be included in the production line if necessary.

How to correctly determine the hole diameter?

Before cutting a thread, a hole is made, the diameter of which is determined according to standardized tables. If you prepare a hole whose cross-section is smaller than the recommended size, the tool will fail; if it is larger, the result will be of poor quality.

Correspondence table for metric threads and hole diameters for them

Thread designation	Diameter, mm	Thread designation	Diameter, mm	Thread designation	Diameter, mm
M 2	1,6	M 8	6,7	M 22	19,4
M 2.2	1,75	M 9	7,7	M 24	20,9
M 2.5	2,05	M 10	8,5	M 27	23,9
M 3	2,5	M 11	9,5	M 30	26,4
M 3.5	2,9	M 12	10,2	M 33	29,4
M 4	3,3	M 14	12,0	31,9
M 5	4,2	M 16	14,0	M 39
M 6	5,0	M 18	15,4	M 42	37,4
M 7	6,0	M 20	17,4	M 45	40,4

Correspondence table for inch threads and hole diameters for them

Thread size, inches	Diameter, mm	Thread size, inches	Diameter, mm
1/8	8,8	7/8	28,1
1/4	11,7	1	30,5
3/8	15,2	1 1/8	35,2
1/2	18,9	1 1/4	39,2
5/8	20,7	1 3/8	41,6
3/4	24,3	45,2

Stages of thread cutting with a machine-hand tap

Work order:

The first step is marking in accordance with the drawings.
According to the marks, punching is carried out with a sharply sharpened core.
Drill with medium pressure at low speeds. The drill should be at right angles to the surface. Before starting work, the drill is lubricated. If the hole depth is large, then lubrication is carried out not only before starting, but also during operation. The depth of the blind hole should be slightly greater than the length being cut. If there is no reserve, the thread may be incomplete.
The quality of the result can be improved by countersink processing, which reduces the taper and ensures parallelism of the side surfaces.
The tap is secured in the driver, its tip is lubricated and inserted into the hole strictly at right angles to the surface. Make the first turn, lightly pressing the knob from above. After the first turn forward, make a half turn back to remove chips. Particular care is taken when using a multi-tool - it is fragile and easy to damage. It's easier to work with complete models.

The nuances of cutting sheet metal with a guillotine

Guillotines are used for cutting sheet metal at home or in small factories.

1. What can be cut with a guillotine?

Using a guillotine, you can process metal no worse than using factory equipment. Moreover, craftsmen often make guillotine shears at home.

The most common versions of guillotines are models with a direct movement of the knife and with a change in angle. In the first, the knife moves in a vertical position and allows you to cut sheet metal evenly. The use of models of the second group allows not only cutting sheet metal, but also processing reinforcement bars and large metal angles.

The working capabilities of homemade guillotines are usually limited. This is because, unlike industrial designs, which have different types of drive (hydraulic, pneumatic or electric), a homemade device for cutting sheet metal is usually equipped only with a mechanical lever or pedal mechanism. The depth of cut when using homemade installations depends on the amount of force applied by the master.

Using homemade guillotines you can cut:

sheets of black and galvanized steel up to 1.5 mm thick;
stainless steel sheets up to 0.6 mm;
aluminum;
plastic;
cardboard.

When making guillotine shears, you should definitely take into account the type of metal that you plan to process.

2. Operating principle.

Metal cutting using guillotines can be carried out both longitudinally and transversely. Installation options depend on the type of knives installed and their location. When making a cross cut, the knife makes one movement. Longitudinal cutting is accompanied by several movements that will be repeated together with the translational movements of the product. Longitudinal cutting is performed when processing rolls or when it is necessary to cut sheets longer than 2 m.

The guillotine works on the following principle: a sharp knife, under its own weight, is lowered onto a metal surface at high speed. Sometimes the cutting speed or weight of the knife is not enough to cut a certain type of metal or the required thickness. Therefore, the design of the machine is often equipped with an additional element - a lower fixed knife. This setup works like a regular guillotine and scissors.

The presence of an auxiliary element, of course, leads to an increase in the final cost of the equipment, but at the same time it allows you to improve the quality and increase the processing speed of metal parts.