The impact sockets or sockets —also called impact sockets, impact tubes, and shock wrench in English—are sockets similar to sockets that are used in conjunction with an impact wrench to quickly tighten or loosen hex-head nuts and bolts.
They are very robust and durable pieces, which withstand great torsion efforts without deforming or splitting, and which can be used, in addition to the impact wrench, with any ratchet wrench (pipe wrench). However, they differ from the common dice, cubes or tubes in the material, the measurements and the finish. We will see below these differences and why.
Impact sockets: designed to resist
The first difference lies in the chemical and crystallographic composition of the steel used to manufacture it: it must be sufficiently resilient to withstand the sudden torsional stress it receives from the impact wrench without deforming.
They are generally made of steel with a chrome-molybdenum alloy, which gives them the necessary hardness and toughness to withstand stresses without undergoing any type of plastic deformation, also minimizing the elastic deformations that would absorb the energy delivered.
Another notable difference occurs in the termination: they are usually blued (passivated with a layer of magnetite, Fe3OR4) and never chromed; this is so to avoid that, with the efforts of work, the chrome comes off. Optionally, some manufacturers carry out a prior sandblasting, to give the surface a slightly rough matte finish.
The third difference is in the geometry of the hexagons: in the common dies a purely hexagonal notch is made while in the impact dice star-shaped notches are generated, to achieve less play between the head of the screw or nut and the socket.
Lastly, the impact dice they tend to have thicker walls than their normal counterparts.
Types of impact sockets or sockets
There are four types of impact dice: normal, universal joint, metric and deep. All of them can be used with an impact wrench or a common ratchet wrench.
Normal impact sockets
They are the ones we saw earlier; they differ from common keyholes in that their walls are thicker and the internal geometry is star-shaped and not hexagon-shaped. They share these differences with the rest of the types of impact dice.
universal joint sockets
They are those that have a universal joint and allow access to nuts and bolts located in places that are difficult to access.
Being keyholes with a built-in mechanism, they should be used only when it is impossible to reach them with a impact die common.
These impact dice are calibrated for metric hex heads. Although these types of bolts and nuts are not very common in industry automotive, it is common to find them in factories and workshops outside of English-speaking countries.
When the screw to be removed or inserted is embedded in a deep hole, it is necessary to use depth sockets, which allow the head to be reached without the need to use extensions not suitable for impact wrenches.
With the impact sockets for depth ensures safe removal or insertion, with dies carefully designed to withstand torsional stress without warping or breaking.
Precautions and tips for use of the impact wrench
- Always wear protective glasses when using a impact die. There is always the possibility that a piece of material will break or come off and, due to the high speed with which they are worked, this fragment can be dangerous for the eyes.
- You can use the impact sockets with common sockets but you should never use sockets with impact wrenches; these are not designed to withstand the torque of that tool, and could be deformed or split, thus producing a dangerous situation for the operator and his surroundings.
- Store the impact dice in a warm and dry place. If this is not possible, always remember to cover the surface of them with mineral oil, to avoid any corrosion.
- Never use a impact socket showing cracks or corrosion.
- Before using a impact die universal joint, try a impact die common; if with this the task is not possible, with one of depth. Only use the universal joint as a last resort, as the mechanism, given the nature of the operation, can suffer with prolonged use.
- Never use a impact socket of a measurement that is not exactly the same as that of the bolt or nut you are trying to tighten or loosen, even as a last resort. It will only damage the socket and irreparably deform the head of the screw or nut.
- The impact sockets they should be used straight only – never use shims or accessories of any kind with them, especially extensions that are often used with traditional sockets. Those accessories are not designed to withstand the stresses in this application, and will only break them.