Square drive size
The size of the "seat" for which the socket heads included in the package are designed (see below), in other words, the size of the square hole on the back of the head used for installation on a ratchet, wrench or other similar tool. Accordingly, the tool for working with heads supplied in the kit has the same dimensions of the landing square; and in the absence of such tools in the kit, data on the size of the heads will be useful for its selection.
There is a generally accepted standard for these sizes, providing for the designation in fractions of an inch — from 1/4 "to 1". Thanks to this, heads and tools from different sets can be quite compatible — just matching in size is enough. Most often in modern hand sets there are options in 1/4 "and 1/2", a little less often — 3/4" and 3/8". Some sets include several variants of the landing square at once.
Socket heads (E-profile)
The number
of E-profile sockets supplied with the tool kit.
All end heads are accessories for a collapsible tool; during operation, they are mounted on a ratchet, wrench or other similar device. The head itself has the appearance of a characteristic “cap”, which, during operation, is put on a bolt, nut, etc. This design, among other things, allows you to work with parts located in recesses and some other hard-to-reach places that cannot be reached with open-ended, captive or split keys. And compared to a set of classic socket wrenches, the holder plus socket set takes up much less space, providing almost the same functionality.
Specifically, this type of heads has a working part in the form of a six-pointed star, which is why such nozzles are also called “asterisks”, “Torx” or “internal Torx”. The latter option is used to avoid confusion with Torx keys (see above): the working part of such a key (“external Torx”) has the form of a star-shaped rod, while in the end head the working part has the form of a recess with similar outlines. As for the use of such heads, when used with “native” fasteners, the E-profile allows you to work at high forces without much risk of breaking the edges; and fasteners are used for such tools, in particular, in cars.
Hex wrenches
The number of
hex wrenches supplied in the kit. Note that some modern kits include
only hex wrenches, without any other fixtures or accessories. It is also worth emphasizing that in this case we are talking about the simplest hex wrenches. Imbus tools — similar in purpose, but different in design — are highlighted in our catalog in a separate category (see below),
Keys of this type usually have the form of L-shaped handles made of a hexagonal rod. Thus, the user can work with both the short and long side of the key; in the first case, the long part of the letter "G" works as a lever, providing a good effort, in the second — it plays the role of an extension. And such tools are used for bolts and other similar parts with a hexagonal cut in the cap. Such splines have a number of advantages over the classic straight and cross splines (in particular, better tolerating high torques), which makes them quite popular — in particular, in bicycles.
As for the quantity, it is worth considering here: sets with the same number of keys of the same type may differ in the specific sizes of these tools. Such nuances should be clarified before buying separately.
Hex wrenches size
Working size range of hex wrench sizes (see above) supplied with the kit. This parameter allows you to evaluate how the keys fit the dimensions of the fasteners with which they are planned to be used.
