The primary and most historically interesting mentions of wrenches are found in 15 century. They spread only somewhere 19, when Mauser actively began to produce them in various industries. Also in 19 — 20 century registered a huge number of patents, modifying different key models.
The apparent simplicity of this design is nevertheless very practical. The wrench is also used when assembling cars, when working in general with a huge layer and the amount of any equipment. And models, designed to work on the ISS, only modifications under standard space conditions, old, the original variant of the invention.
First, for a large number of key variants there was absolutely no classification. This was due to their large number, as well as the large number and variety of patents for them and similar types of devices. However, Nonetheless, early 20 century there was a final division. The main classification feature was recognized as a system:
- metric;
- inch.
As you can guess, it is now difficult to determine the authorship and the original inventor.
Types of wrenches
Technical definition of the tool
What definition can be given to a wrench? This is a tool, which is used to disconnect or connect the threaded fasteners by twisting or unscrewing the nuts, bolts, as well as other various details. In general, wrenches can be divided into two groups:
- cover;
- covered.
Standard, hole size (throat) spelled out in the parameters defined by the rules and measured in fractions of an inch, so-called inch keys, or in millimeters (metric keys).
Common phrases "key on 14" or "key on 11 and the like, which describe the sizes of wrenches, mean, that the hole size of this key is equal to 14 or 11 millimeters, respectively.
Types of wrenches
In addition to the above division into covered and covered, keys can be divided into many types, which will take a long time to describe. Let's try to describe some of the most popular and used quite often in many aspects of various works.
It:
- carob;
- cap;
- combined;
- adjustable;
- end;
- tubular;
- keys with a rattle;
- others.
The most common options
To begin, consider the horn key. In principle, when many of us take the first association with the phrase "wrench", then in front of them, as in the photo, there is a picture of a horn key. In such a tool, the nut is fixed between the jaws, which are able to resemble horns. Hence the name of this type of wrench. In such the longitudinal axis of the head and the longitudinal axis of the handle, usually, are at an angle and this angle is equal to 15 degrees.
There are other variants of this tool with a different angle relative to the head and handle, in one key options can be combined. In principle, this solution is used to facilitate the work of the owners of the tool in a limited space.
Such wrenches are used almost everywhere and this is explained by their simple design and relative versatility.. However, Nonetheless, such keys have their significant shortcomings. The key is that, that such a tool has only two small contact areas, which are at the same time close to the corners of the nut. The pressure on these areas often tends to compress the corners of the nut and, usually, this occurs when the size of the throat is slightly larger than the size of the nut. With a little effort, the corners will wrinkle. If the size of the hole exactly matches and adheres to the nut, then crumpling can also occur only with a little more effort.
If you reduce the thickness of the lips of the key, then the probability of damaging the nut increases.
Cap or ring tool is a better way to work the way you want. Its design eliminates two small contact spots, which were described in the previous paragraph. The cap tool covers the entire nut or bolt. Thus, the number of contact spots increases to six (on the faces of the bolt). However, they are all a little further from the corners, which eliminates their crumpling. The head is slightly smaller, in general, it is much more convenient to work with such a tool.
The ring can lie in one plane of the handle (the so-called flat key), may be at some angle (called such a tool with a bent head). Usually, the angle is equal to 15 degrees. It is also possible to have a bend. Some options allow a hinged head. Situations occur when servicing hydraulic or pneumatic systems, when it is impossible to throw the tool from above and for such cases make apertures in a ring, translating it into the category of open.
Combined tools usually combine horns and caps. One ring on one side, on the other - another. This allows you to create a tool, devoid of the shortcomings of any of the individual species. At the same time, manufacturers are not limited to combining only these two options. More modified options have an angle of 90 degrees, under which the head is inverted, and in this case the palm rests on a wide plane which is convenient at work.
Less popular types of nut tools
Adjustable nut tools are horn options with variable spacing between the jaws. Often used in everyday life, dislike of professionals is due to many factors and, in particular those, that the mechanism of the movable head wears out over time and the backlash relative to the nut becomes larger. It, given that, that even in an integral state backlash of a movable sponge does not allow to compress a nut completely, which forces even more effort, increasing the chance of damaging the mounting mechanism and bolt. Plus - the relatively large size of the head can be a serious obstacle when working in hard to reach places.
End nut tools have a hexagonal recess. It covers the bolt. Often the shape of such a tool is L-shaped, and a hexagonal recess is on both sides. The end tool can have a twelve-sided recess. In general, possession of a dodecahedron notch instead of a hexagonal leads to that, that at work it is enough to turn the tool on 30 degrees. The notorious corners of the bolt suffer less.
The form of the T-shaped tool with one head is also possible, complete set of replaceable heads or a cross-shaped form is allowed.
A tubular nut tool is a tube, at the ends of which a hexagon is made. There are holes for the rod, which acts as a lever and called a cell. Such simple mechanisms can sometimes be equipped with machines, cars and equipment.
Ratchet nut mechanism is a kind of modification of the end and cap version with ratchet details. The main advantage of this type of tool - you do not need to throw it when working directly. Also important is a small angle of rotation when tightening the screw or nut. The presence of a rattle mechanism 72 teeth reduces the angle to 5 degrees. The downside is that, that the rattle is a weak spot and breaks under strong influence, and the price of such a tool has higher parameters.
Specific equipment options
Other options include a knitting tool and a bicycle wrench, that many may be familiar with from childhood. The version of the colic mounting tool is interesting, that the other end of it is a tapering rod. There are nutcrackers, used when removing attached nuts. If the nut is not hexagonal, and round, and you have to remember, what happens, then a special tool must be used to screw or unscrew it. Pipe mechanism is popular with plumbers, and special chain wrenches are used for round parts, having a large diameter.
Reasons for diversity
In general, we can say, that the types of wrenches are very diverse. Because of that, that they are needed for various nuts and bolts, a, exept this, also used in a variety of situations, it turns out, that somewhere you can use one view, well, somewhere completely different. The basis for such diversity is always a nut or bolt. They can be located and attached in completely different ways, they can be strikingly different sizes. And in the end it all comes down to that, how to approach them. Manufacturers in the market for this type of goods always, and even more so now, there were many. As a result, prices vary widely.
And finally. Those, those who often do car repairs can give advice to beginners, appropriate for nut tool kits from the manufacturer. Such selections of different key sizes do not always include those types and sizes, which you would expect to see in yourself at that moment, when you enter the car (pit or flyover). Not finding the item you need, you will have to get out of an awkward position, look for the necessary part of the kit and climb back again.
That's why always, before, how you decide to repair the car, mentally think about what work you will need to do and take care of it, that all things necessary for this work appeared to you at once, so as not to burden yourself with unnecessary fussy movements.