Total number of items
The total number of items in the set. In this case, both the actual
bits and end heads are taken into account, as well as additional accessories such as an adapter, a bit holder, etc.
The more items in the set, the wider its possibilities. However, note that the specific composition of the kit may be different, so when buying it is worth specifying not only the number of items, but also their specific types.
Landing square
The size of the square of the bits / sockets supplied in the kit.
The seat square is a standard fixture used in bits and sockets. For installation on a bit holder, ratchet, etc., the size of the square must correspond to the size of the seat. However, complete fixtures (like the same bit holder) by definition have fasteners of the right size, so you have to pay attention to the size of the square mainly if you plan to use nozzles with third-party tools.
Also note that the overall dimensions of the complete bits / heads can be estimated from the landing square: the larger the square, the larger the nozzles. For example, in 1/2" sockets, the size starts from 8 – 10 mm, and in 1" sockets — from 24 mm.
SL bits (Slot)
The total number of
bits of type SL supplied in the set.
Marking SL means bits with the simplest flat tip. For such a tip, in principle, strict compliance with the size of the slot in the fastener is not necessary — it can be a little narrower or a little wider. In addition, flat-slot fasteners are used relatively rarely today, more advanced varieties have become more common. Therefore, the SL-type bit in the kit, usually, is not much.
SL bits sizes
The sizes of the SL type bits included in the set and the number of bits of each size.
For the bits themselves, see above. The size is indicated by a number indicating the width in millimetres; if the bit is more than one, after the size their number is specified. For example, the marking "SL4, SL6x2" means one bit for 4 mm and two for 6 mm.
PZ cross bits (Pozidriv)
The total number
of PZ type bits supplied in the set.
The PZ is a modified version of the PH cross tip (see the relevant paragraph). In PZ tips, the angles are more pronounced, there are additional edges to increase the contact area with the slot — thanks to this, unlike PH, these tips do not push out of the slot even with a very large effort. All this makes the PZ a fairly convenient option for working at high loads, including uneven — in particular, for tightening self-tapping screws.
PZ bits sizes
The sizes of the PZ type bits included in the set and the number of bits of each size.
For the bits themselves, see above. The size in this case is indicated by a conditional number; the larger the number, the larger the slot for which the nozzle is designed. If there is more than one bit, the number of bits is specified after the size. For example, the entry "PZ1, PZ2x2" means one relatively small bit and two larger ones.
T bits (Torx)
The total number
of Torx bits supplied in the set.
The Torx tip has the shape of a six-pointed star. This provides a larger area of contact with the fastener than flat and cross bits, and allows you to work with higher forces.
T bits sizes
Sizes of the Torx type bits included in the set and the number of bits of each size.
For the bits themselves, see above. The size in this case is indicated by a conditional number; the larger the number, the larger the slot for which the nozzle is designed. The specific size to which this or that number corresponds can be clarified according to special tables. If there is more than one bit, the number of bits is specified after the size. For example, the entry "T7, T8x2" means one bit of T7 and two of T8.
TH Bits (Torx Hole, Torx Security)
The total number
of Torx Security bits supplied in the set.
Torx Security (also Torx Tamper Resistant) is a variation of the Torx tip (see the relevant paragraph), supplemented with anti-vandal protection. On fasteners, this protection has the form of a pin in the centre of the star slot; accordingly, Torx Security lugs differ from regular Torx lugs in having a hole for a pin. At the same time, bits of this type are also suitable for conventional Torx fasteners, but not vice versa.
