Do-it-yourself straightening tool: making a body hammer and its types

reverse hammer

Among the works related to body repair, the most difficult is straightening, which is understood as the alignment of body parts. This is due to the high requirements for the skills of the performer for its high-quality performance. In addition, you will need professional tools, such as, for example, the hammers discussed in the above article, including a reverse hammer for body repair.

Reverse hammer: device

This term is understood as a metal pin 50 cm long and 2 cm in diameter, one side of which is represented by a sleeve, and the other side by a small steel washer that holds the sleeve and protects the body from shock vibrations. Many models of reverse hammers are equipped with several hooks that serve to capture staples welded to the body.

Purpose and classification

The reverse hammer is designed for leveling small dents that are not directly accessible from the back on parts such as sills, arches and pillars.

It should be borne in mind that the tools in question are not suitable for processing large body parts, such as the roof, hood and trunk lid.

In addition, with the use of reverse hammers, only small dents can be removed. In the case of, for example, violation of the geometry of the body, other repair technologies will be required.

Homemade Reverse Hammer

Reverse hammers are classified into four types:

  • vacuum;
  • spotters;
  • with two and three weights;
  • with pneumatic mechanism.

The type of tool determines the technology for the implementation of straightening work. In the case of using reverse hammers of the last three types, it is first necessary to completely remove the paintwork material from the surface of the machined body part by grinding. The difference between a vacuum tool is that it is used without removing the paintwork, without damaging it and without compromising its integrity.


Do-it-yourself straightening process using a reverse hammer is performed in the following order:

  1. First of all, it is necessary to clean and degrease the work surface.
  2. Then the paintwork is removed from it by grinding.
  3. Round repair washers are welded onto the machined area of ​​the body.
  4. Next, the supplied metal hook is attached to the end of the reverse hammer.
  5. He is hooked on the puck and, holding the weight with one hand, and the handle with the other, the first is directed to the second with sharp movements. In this case, the surface of the body part is leveled. It should be borne in mind that the force of impacts directly determines the leveling speed.

Working with a reverse hammer

Dents lead to the formation of internal compressive and tensile stresses, which can change unpredictably during straightening. For its successful implementation, it is very important to determine the nature of the defect. For example, when removing a dent located in the central part of a body part, new defects may form by pulling.

Therefore, in the process of straightening, it is necessary to control changes in the corrected dent and, in order to avoid the formation of new defects, carry it out from the edges to the middle of the defect in a circle.

If the work is done correctly, the surface will take its original shape, and the deformation stress will be eliminated.


Reverse hammers can be purchased separately or in special tool kits for body repair. In addition, this tool can be made by hand. For this you will need the following materials:

  • a steel pin with a diameter of 2 cm, a length of 50 cm (you can use a smaller diameter option, however, in this case, the service life of the tool will be shorter);
  • handle made of ebonite or rubber (an ordinary nozzle is also suitable);
  • welding machine;
  • stainless steel hook 4-5 mm thick;
  • weight 16-17 cm long, 6 cm thick;
  • two washers made of steel with a diameter of 2.5-3 mm.

homemade spotter

The following is a sequence of work on making a reverse hammer with your own hands.

The metal pin must be cleaned, if necessary, given a smooth surface by grinding, and degreased. Attach a hook to one end of the pin. This can be done in two ways: by welding, or create a thread and screw onto it. Welding a hook is much faster, however, having created a thread, it will later be possible to use various nozzles. Then you need to put the washer on top, twisting or welding it near the base of the hook. Thus, the possibility of moving the weight to the surface to be treated during the straightening process will be prevented.

A hole is made in the weight with a diameter of 0.1 cm larger than the diameter of the pin to enable it to move freely during operation, and it is put on from the free end of the pin. If the stroke is tight, the diameter of the hole in the weight is increased by another 0.5 cm. The weight itself should not have corners and protrusions, since in this case its movement during operation will be difficult. To ensure the greatest grip comfort, steel round sheets should first be welded to both ends of the weight so that the hand does not slip off it. Another washer is put on top of the weight and fixed, which is necessary to prevent the weight from moving close to the handle during operation. Finally, put on and fix the handle.

As you can see, the work on making a reverse hammer is quite simple to do with your own hands. The whole process takes 30-40 minutes.

Other straightening hammers

In addition to the reverse hammer, there are some other types of hammers designed for body repair, such as pick and shrink. However, all models of straightening tools of this type have some common features.

The strikers of such hammers are made of rubber or some other elastic material. This is necessary to ensure a soft effect of the hammer on the surface to be treated during the straightening process. This eliminates defects without causing new damage to the material. Leveling options for tools are equipped with handles that expand towards the end, often with rubber pads. They provide a comfortable grip, secure hold of the tool and prevent it from slipping out of your hand.

Many straightening tools provide the ability to change nozzles from various materials that come with the kit, thanks to the presence of a thread on the handle.

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