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 sizes (6 points)
Working size range of hex sockets (see above) supplied with the kit. This parameter allows you to evaluate how the heads fit the dimensions of the fasteners with which they are planned to be used.
Socket heads sizes (E-profile)
Working size range of E-profile sockets (see above) supplied with the kit. This parameter allows you to evaluate how the heads fit the dimensions of the fasteners with which they are planned to be used.
Wrench sizes
Dimensions of the wrenches supplied in the set. Specified as a range — from the minimum to the maximum size. In this case, the specific distribution of different types of keys over the range may be different. An example is the following set: 17 open-end wrenches, 5 box wrenches, size range 6 – 24 mm. In such a set, box wrenches are almost guaranteed not to cover the entire range of sizes, but for open-end wrenches, this is quite likely. Such details can be specified separately.
Also note that a wrench size of
24mm or more is considered quite large for today's general purpose tools. However, on the market you can find sets that include wrenches for
27 mm,
30 mm and even
32 mm.
Weight
The total weight of the tool kit. Indicated with a case, stand or other storage/transportation device (see Tool Storage). First of all, you should pay attention to this parameter if you plan to often carry the kit over long distances — the lighter the weight, the easier it will be to do. At the same time, extensive sets inevitably turn out to be weighty.
