Wrenches
A wrench is a hand tool for tightening and loosening rotating fasteners such as nuts and screws. There are several types of wrenches: open-end, box-end, combination, flare nut wrenches, and tubular.
Higher-quality wrenches are made of chromium-vanadium alloy tool steels. They are often chrome-plated to be corrosion-resistant and easier to clean.
Open-end wrench
Open-end wrenches are used to tighten screws (nuts) with a six-sided head. Because of the open end, this type of wrench can be easily placed on a bolt or nut. The set of wrenches usually contains sizes from 6 to 27 mm, and the ends are arranged in sizes 6-7, 7-8 … The wrench opening is usually at an angle of 15 ° about the handle. This allows a wider range of key movements in a confined space. So, if we can’t turn it by the full 60 ° it takes to put it back on the hex nut, then turn the wrench, tighten it, turn it again, tighten it, and so on until the end.
Open-end wrenches are used because they have good access to the nuts. However, if the nut is too tight, avoid this unscrewing wrench because it grips the screw only at two points. By applying a stronger unscrewing force, there is a danger that the wrench will slip around the nut and damage it.
Box-end wrench
The box-end wrench fits fully around the head of the bolt or nut and grips each of the six points at the corners. These wrenches can be tightened much more reliably on the screw than open-end wrenches. There is little chance of the wrench slipping and damaging the nut when unscrewing.
The position of the wrench in relation to the handle can be in the direction or the knee. The knee wrench is more convenient for screws in inaccessible places. The only drawback is the use when the screw is loosened a bit because it is harder to move and put in a new position.
Box-end wrench
Combination wrench
This type of wrench has an open-end on one side and a box-end socket on the other. Both ends are the same size. The box-end wrench serves to loosen and the open-end wrench for further unscrewing the screw. Due to its versatility, this key is very popular with service technicians.
Flare nut wrench
It is used for tightening nuts on the tubing. The average wrench looks like an open-end wrench, only one side is average so that it can be placed over the pipe. This wrench covers the nut better than an open-end because it rests on all six points and not just two. However, since it is open in the end, it is not as strong as the box-end wrench. Do not use this wrench on tight nuts as of may spread and damage the nut head.
Flare nut wrench
Tubular wrench
Tubular wrenches are used for nuts deep in the holes. The turn of the wrench is done using a transverse lever which is inserted through two holes in the middle of the pipe. Due to the even pressure on all edges of the nut, there is no danger of slipping. Typical representatives of tubular wrenches are the wrench for spark plugs and wheel nuts.
Using wrenches
Choosing the right wrench usually depends on two things: how tight the nut is and how much space there is around it to turn.
When a wrench is used there is always the possibility of it slipping off the screw. Before you use more force, try to predict what will happen if the wrench slips. Whenever possible, it is better to pull the wrench towards you than to push it. If you have to push the wrench, use your palm as you may injure your fingers if it slips. If pulling toward yourself, make sure your face is not close to your hand or in line with your pulling motion. Many technicians have punched themselves in the face when the wrench slipped.
The lengths of the wrenches are usually so long that you cannot destroy the thread on the nut or nut when turning by hand. It is not recommended to extend the key by inserting a pipe or hitting the key with a hammer.
