Forged wickets and gratings are becoming increasingly popular. In addition to protecting against intruders entering the house, they also perform a decorative function. Traditionally, blacksmiths gave shape to steel products, preheating them to high temperatures (to a red glow). It is far from always possible to organize a full-fledged forge at home for a variety of reasons. An alternative is cold forging. With your own hands, you can easily assemble a device for bending steel bars and strips in the cold state.
Features of cold forging
In the old days, people who forged metal enjoyed incredible prestige among fellow villagers. Some even ranked them among sorcerers: the forging of steel products was so spectacular and indicative. This profession was considered prestigious. In our century, the age of high technology, the work of a blacksmith may no longer be the ultimate dream of young people. Many people do it as a hobby, for the soul. But nevertheless, the work of a blacksmith is very important and necessary. The industry has mastered the production of a wide range of steel grades. It has become possible to shape metal, avoiding hazardous open fire work. This method of forging is called cold, and everyone can organize a workshop for cold forging. For this, a barn in the country, a garage in the city, and even a basement of an apartment building will do.
If you want and have the time, decorative grilles and decoration for the fence can be made with your own hands. Cold forging, as the name implies, does not provide for pre-heating the workpiece to temperatures sufficient for recrystallization processes to occur. This means that such a process is not so expensive, simpler technologically, eliminates the threat of fire, burns and serious injuries.
Pros of Cold Forging
As already mentioned, cold forging does not involve heating the metal. And this means that you can significantly reduce the process, make it safer and more economical.
Even if previously there was no experience in metalwork and installation, nor in cold forging, making a bending machine with your own hands will not be difficult. To do this, you need only the necessary tool, desire and determination.
Cons of cold forging
Yes, this process is quite simple and easy to do. Cold forging is certainly a good alternative to traditional blacksmithing. But the possibilities of such a process are limited.
In the cold state, not all steels and alloys can be processed. So, high-carbon steel (with a carbon fraction of 0.65) is difficult to deform in the cold state. Special alloy steels are also very resilient. In this way, as a rule, steels of ordinary quality with a low carbon content are treated, sometimes structural low-carbon steel. Moreover, the blanks (rental) should have a cross section of a small area. Otherwise, they will not deform.
During the deformation of steel in the cold state (at room temperature, and generally below the temperature of recrystallization), a huge number of defects in the crystal structure arise in its structure. On the one hand, this leads to an increase in strength characteristics (the so-called phenomenon of metal hardening), and on the other hand, steel becomes more fragile. If the steel is heated, then a redistribution of the lattice atoms occurs (point defects are eliminated).
Summing up, we can say that the main advantage of the process under consideration is the simplicity and the ability to do it yourself. Cold forging, on the other hand, degrades the performance of steel.
Cold Forging Tools
Although the blacksmith's labor consists largely of manual work, most operations cannot be done without the use of cold forging accessories. With your own hands, without the use of auxiliary devices, it is hardly possible to twist the bar into a uniform spiral (the so-called snail is used for this), make bends of a given curvature (a tool is a bend). Devices, as a rule, are made universal and can work with rolled products of various sections.
The design of the devices is quite simple, and therefore they can be made in the home workshop with your own hands. You can also make a cold forging machine yourself. This is even better than buying finished equipment. However, it should be noted that the working parts of such equipment must have high wear resistance. It is best to use high-strength die steels or tool steels for these purposes. Otherwise, the device will quickly become unusable.
The principle of operation of the cold forging machine
In blacksmithing, the concepts of “machine tool” and “fixture” have the same meaning. The principle of operation of devices and machines can be reduced to the following. The workpiece is installed in the appropriate socket. Next, the free end of the bar is started with the auxiliary lever and rollers in the necessary direction. Sometimes such machines and devices are equipped with mechanical and electric drives. But in this case, it will be a full-fledged industrial bending machine, and not a do-it-yourself cold forging machine. Such equipment is very expensive. It can also be equipped with a CNC system.
Description of Twister
This device is easy to assemble with your own hands. Cold forging equipment is designed to twist rolled stock. One end is fixed motionless in a vice, and the other is fixed in a cartridge. The cartridge is driven either manually or by means of an electric drive.
Source ponds can have a variety of lengths. Therefore, when designing and assembling such a machine, it is necessary to provide for the possibility of moving the vice in the longitudinal direction. Moreover, the vise must be free to compensate for the reduction in the length of the workpiece during twisting.
Description and principle of operation of the lever machine
In terms of appearance and design features, such equipment is similar to pipe bending machines. Performance is pretty low. At the same time, the load on the operator is quite large, as a result of which fatigue quickly sets in. For this reason, the base must have greater rigidity. On one snail, you can get several different turns. The pressure roller experiences the greatest load, for this reason it should be made of high-strength alloy steel. It can be made of carbon steel, but with subsequent hardening of the surface layer by methods of chemical-thermal treatment: nitriding, boronation, alitizing. As such a roller, a roller bearing roller can be used, as it is made of special bearing steel 15 and is able to withstand very high contact loads.
How to make a do-it-yourself snail for cold forging
Such a pattern is the most common tool for giving steel products the necessary shape. To work with such a device is elementary simple, and all operations can be carried out without assistance, with your own hands. The dimensions of the coils for cold forging can vary and depend on the rod of what diameter and length will need to be forged (bent).
There are many designs of snails. But they all have an extremely simple design. The easiest way to make a pattern of wood, and then surround it with sheet steel. Such a design will wear out quickly with frequent use. However, for the home workshop this is the best option.
How to make a matrix press
This equipment is classified as semi-professional. The hardest part is to make the mold itself. For this, most likely, you will have to contact a specialized engineering company. If the stamp has a complex developed shaping surface, then it must be machined on a 5 coordinate CNC milling machine. Such services are not cheap. Therefore, if forging metal is just a hobby that you can do on weekends, it is not practical to buy such equipment. If metal forging is the main source of income, business, and equipment is loaded with work, then in the end it will still have to partially mechanize manual labor. Such equipment can also significantly increase productivity.
The working matrix is installed on a special hydraulic press. If the budget is limited, then you can make a welded structure and equip it with a jack.
Preparing to assemble the machine
Each of the listed devices can be made at home. However, it is better, of course, to entrust the manufacture of individual critical parts and assemblies to specialized companies in the field of metalworking. This will increase the cost of the product, but at the same time ensure its reliable operation. Therefore, it is better to outsource these works than do it yourself. Cold forging metal on good and reliable equipment will be a pleasure.
To assemble the machine you will need the following tools:
- Grinder with a circle for metal. This tool is indispensable when cutting a metal profile, removing rusty bolts and nuts.
- Roller bearings
- Bench drill machine.
- Required hardware: bolts, nuts, screws.
- Tool kit for threading: dies, taps, knob.
- Heat treatment furnace for individual critical parts.
Before proceeding with the assembly, it is necessary to draw a general drawing of the structure, as well as working drawings of the individual parts.
Assembly of a typical machine
Both the machine itself and the accessories for it can be made with your own hands. Both cold forging and other operations associated with the processing of steel and giving it the necessary shape, need certain skills. Assemble the machine yourself, without the help or at least the consultation of a knowledgeable person, is unlikely to succeed.
As a rule, cold forging workshops are equipped in very small rooms. And therefore, it is important that the equipment and machines are universal. In other words, in order to save space and money, it is recommended to make such machines so that various devices can be installed on them.
As a rule, several holes are drilled into the plate, to which different snails can be attached. The lever with a roller is attached to one of the corners of the table and is non-replaceable.
On the side of the machine there are fingers for installing the gnut. By replacing the rollers, it is possible to obtain a different radius of curvature of the bar.
A typical machine (fixture) is shown in the photo. DIY cold forging is a hobby of many people. Some were able to turn their hobby into earnings, and not bad. With the help of such simple devices, real masterpieces are created, without exaggeration.