To harden a spring means to subject it to heat treatment in order to increase the strength, elasticity, hardness and ductility of the product, which will ultimately affect the physical and chemical properties and service life. The essence of the process is heating to a temperature at which the metal structure transforms into a special state, and high-speed cooling in various environments, including cooling in air. The choice of hardening technology depends on the grade of steel from which the spring is made and the diameter of the wire. This operation is performed in industrial and home conditions.
A homemade spring is not recommended for use in devices operating under increased loads.
Do-it-yourself spring manufacturing and hardening technology
Almost every home craftsman knows that it is possible to make a spring from almost any wire and successfully use it in everyday life. Basically, there are no problems with making the part yourself. However, sometimes situations arise in which it is necessary to either make a spring of non-standard dimensions, or give it increased strength and elasticity. To do this, you should resort to heat treatment operations. It is quite possible to harden a spring at home. It goes without saying that a homemade part should not be used in particularly critical devices operating under increased load. For such purposes, it is recommended to use factory-made springs. But for home use in a device operating in a lightweight mode, the technology in question is quite suitable.
- Required tools and materials
- Features of the operation
- Sequencing
Cold coiling technology without hardening
First you need to do preparatory operations. Before a workpiece is wound from wire, it is subjected to a patenting procedure. It consists in heating the material to the plasticity temperature. This operation prepares the wire for the upcoming change in shape.
During the winding operation the following parameters must be maintained:
- External diameter of the product (for some parts the internal diameter is standardized).
- Number of turns.
- Winding pitch.
- The total length of the part, taking into account subsequent operations.
- Compliance with the geometry of the end turns.
Cold coiling without tempering
Next, the end turns are ground down to a flat state. This must be done to ensure high-quality support for other structural parts, to prevent their destruction and the spring from slipping out.
The next stage of the technological process is heat treatment. Cold coiling of springs involves only tempering at low temperatures. It allows you to increase elasticity and relieve mechanical stresses that arise during winding.
It is extremely important to strictly adhere to the design heat treatment schedule, carefully controlling temperature and holding time.
After heat treatment, it is necessary to carry out test and control operations.
Further, if necessary, protective coatings can be applied to prevent corrosion. If they were applied by galvanic method, the products are reheated to reduce the hydrogen content in the surface layer.
Required tools and materials
In order to make and harden a wire spring with your own hands, you need:
- Steel wire. The diameter is selected based on the necessary characteristics of the future product.
- Ordinary gas burner.
- Metalworking tools: pliers, hammer, etc.
- Vise.
- Stove. This may be, if available, a special one or an ordinary household one.
Additional devices that are selected individually in accordance with the size and stiffness of the spring can facilitate the process of winding the spiral.
If the use and hardening is intended to be made from wire with a diameter of less than 2 millimeters, then it may not be preheated. It will bend without any problems without this operation. However, before starting winding, it is recommended to straighten it along its entire length and completely level it.
When using wire with a diameter of more than 2 millimeters, it should be burned before starting work. Without this operation, aligning and winding it will be problematic.
Heat treated springs for corrosion protection
Heat treatment of springs is a generalized name for operations such as heating, holding and cooling of these products.
The main goal of such processing is to obtain the specified parameters and properties of elastic products, which is achieved by changing the internal structural structure of the metal alloys used in each specific case. To achieve this goal, steels/alloys are heated to a certain temperature, maintained under such conditions for a precisely specified time and cooled, depending on the technology, in a fast or slow way.
Such processing may be an intermediate operation in the technological process of manufacturing elastic parts, in which case it serves to improve the results of subsequent operations (pressure processing, cutting, etc.). If such processing is the final stage of the technological process, then it is carried out to ensure the specified properties of each product.
Features of the operation
- The right foundation is the key to success. In factory conditions, an alloy of non-ferrous metals (65G, 60HFA, 60S2A, 70SZA, Br. B2), alloy or carbon steel is used for production. During home production, the optimal base will be an old spring of the required diameter.
- A special furnace is best suited for annealing. If this is not available, brick or metal will do.
- For cooling after heating, it is recommended to use transformer oil. If it is not available, a spindle will do.
Sequencing
1. Before tempering the spring wire, you should check the base material and make sure that the wire used is carbon steel.
2. The annealing procedure, as mentioned earlier, can add plasticity. This will make the process of alignment and winding onto the mandrel easier. You can use a special oven or any suitable oven for this. In everyday life, it is possible to harden in the most suitable structure (metal or brick). To do this, a regular fire is lit and then the future spring is placed in the coal. After heating the workpiece red-hot, the wire must be removed and allowed to cool naturally. The cooled wire will be much softer and you can work with it comfortably.
3. The softened wire should be completely aligned and begin winding onto a mandrel of a suitable diameter. During the procedure, you need to control the tight arrangement of the turns to each other. To make it easier, you can use a screwdriver.
4. To impart the required elasticity, hardening will be required. Thanks to this heat treatment, the part is harder and more durable. Hardening springs involves heating them to a temperature of 830 to 870 degrees. To do this, you can use a gas burner. Earlier we talked about hardening metal at home.
It is unlikely that you will find a suitable thermometer at home that can accurately determine the temperature of a part. Therefore, you can navigate by the color of the metal. When the required temperature is reached, the workpiece will turn light red. We recommend watching a video with a detailed description of the heating temperature. After this, the spring is placed in a cooling medium (oil).
5. Afterwards, the hardened spring must be kept in a compressed state. This requires from 20 to 40 hours.
6. Finally, process and adjust to the required dimensions.
Correct implementation of such hardening will allow you to successfully use the spring in home mechanisms.
Useful recommendations for masters
When creating such products with your own hands, it is enough to follow the simplest recommendations from professionals:
- The wire must be straight. If the spring is made from old material, the wire must be aligned.
- The rod must be clean from rust and other dirt. For this, a solution of soda or store-bought substances are suitable - household chemicals for removing rust and dissolving oils.
- It is recommended to wipe the wire after cleaning not with a cloth, but with sawdust.
- Steel with a diameter of more than a couple of millimeters must be burned red-hot (around 400 degrees Celsius) before being wound, and then cooled in the open air.
- During winding, it is necessary to carefully monitor the location of the turns in relation to each other.
- You can harden springs at home in several ways: in the stove, using a gas burner, and over a fire. The steel should heat up to almost 900 degrees.
- It is worth recalling that due to too rapid cooling the metal may crack.
- It is recommended to keep the spring created at home compressed for a certain time. Typically this period ranges up to 40 hours. But no less than 20.
Properly performed heat treatment can reduce residual deformation and increase the percentage of elasticity. Hardening allows you to obtain increased quality indicators, thanks to which you can use the spring in any product.
How to make a spring at home with your own hands
Most often, the question of how to make a spring yourself, using improvised means, does not arise. However, there are situations when a spring of the required diameter is not at hand. It is in such cases that the need arises to make this element with your own hands.
Making a small spring is quite possible
Of course, springs for critical mechanisms operating under intensive conditions are best manufactured in production conditions, where it is possible not only to select correctly, but also to comply with all the parameters of the technological process. If you need a non-standard spring for use in a mechanism that will be operated in a gentle mode, then you can make it at home.
Final stage
After the hardening procedure, the spring should be compressed and left in this position for two days. Then, using a sharpening machine, its ends are processed. This will give the handicraft the required size. After completing all of the above steps, the spring is considered ready for use. According to experts, homemade products cannot be compared with similar factory-made products.
However, non-standard springs are widely used in various mechanisms. If they are used in a gentle manner, the springs will last quite a long time.
What you need
To make your own spring, prepare the following supplies and equipment:
- steel wire, the diameter of which should correspond to the cross-sectional size of the turns of your future spring product;
- a regular gas burner;
- a tool that every locksmith workshop must have;
- bench vice;
- a stove, which can also be used as a heating device for household purposes.
It is easier to wind a spiral using devices, the design of which depends on the size and stiffness of the spring
The wire, if its diameter does not exceed 2 mm, does not need to be subjected to preliminary heat treatment, since it is easy to bend without it. Before winding such wire onto a mandrel of the required diameter, it must be unbent and carefully aligned along the entire length of the winding.
When choosing the diameter of the mandrel, you should take into account the size of the spring that you are going to make at home. To compensate for the elastic deformation of the wire, the diameter of the mandrel is chosen slightly smaller than the required size of the internal cross-section of the future product.
Coil spring winding device
If the diameter of the wire from which you are going to make a spring with your own hands is more than 2 mm, it must first be annealed, since without such a procedure it will be difficult to align it and wind it onto the mandrel.
Hot coiling technology with quenching and tempering
Before winding, the workpiece is heated to plasticity temperature using one of the following methods
- muffle furnace;
- gas-burner;
- high frequency heating.
Next, the workpiece is supplied to the coiling equipment. The geometry is adjusted and flat ends are formed.
Heat treatment includes hardening and low-temperature tempering.
Heat treatment schedules are constructed based on the properties of the material and the dimensions of the workpiece.
Operating mode of the quenching and tempering furnace line
Next comes the control and measuring stage. Manufacturing is completed by applying anti-corrosion protection.
Step-by-step instruction
The first thing you need to do if you are going to make a spring with your own hands is to select the material for such a product. The optimal material in this case is another spring (the main thing is that the diameter of the wire from which it is made matches the cross-section of the coils of the spring that you need to make).
By selecting material from an old spring, you will be sure that the wire is made of hardened high carbon steel
Annealing the wire for the spring, as mentioned above, will allow you to make it more flexible, and you can easily align it and wind it on the mandrel. To perform this procedure, it is best to use a special stove, but if you do not have one at your disposal, then you can use any other device that heats wood.
In such a stove you need to light birch wood and, when it burns down to coals, put a spring in it, the wire from which you are going to use. After the spring is red-hot, the coals must be moved to the side and the heated product allowed to cool along with the stove. After cooling, the wire will become much more flexible, and you can easily work with it at home.
The wire that has become soft should be carefully aligned and begin to be wound onto a mandrel of the required diameter. When performing this procedure, it is important to ensure that the turns are located close to each other. If you have never winded springs before, you can first watch a training video, which is easy to find on the Internet.
You can use a screwdriver to wind a small spring.
In order for your new spring to have the required elasticity, it must be hardened. Heat treatment such as hardening will make the material harder and more durable. To perform hardening, the finished spring must be heated to a temperature of 830–870°, for which you can use a gas burner. You can determine that the required hardening temperature has been reached by the color of the hot spring: it should turn light red. To accurately determine this color, also rely on the video. After heating to the required temperature, the spring must be cooled in transformer or spindle oil.
Hardening of the product
For those who are interested in how to make a spring themselves, experienced craftsmen also advise paying attention to its hardening. This procedure consists of heat treatment of the product in order to give it the required elasticity.
A spring that has undergone hardening becomes much harder and more durable compared to its original state. Heat treatment is performed in special furnaces at temperatures from 830 to 870 degrees. You can also cope with this work at home using a regular gas burner. Since there are usually no temperature sensors in such devices, the home craftsman will have to control the process visually. The color of the item being heated can be used as a guide. When heated to 800 degrees, the metal turns cherry red. This means that it is too early to remove the product from the oven. If the spring is hot enough (870 degrees), it will turn light red. Now it should be cooled. Transformer or spindle oil is suitable for this purpose. In special factory thermal furnaces, metals are heated to 1050 degrees. Products at this temperature regime acquire orange shades.
how to make a spring?
The priest had it. In short, there was a tricky spring, but along the way I fell in love with it. It’s impossible to find another one, you have to do it. I tried to bend it out of an ordinary twisted spring, but it didn’t work out very well. After annealing the workpiece, bending is more fun, but you need to heat it up. Here’s the question: how to properly harden a spring at home with a minimum of heating equipment. The diameter of the rod is 1.5 mm, the overall size of the spring is 40 mm X 15 mm (in one plane). Help whoever can
