A slot is a slot on the head of a screw or screw (German Schlitz - slot, slot), designed to transfer torque from the tool (screwdriver or socket wrench) to this product.

Slots are different forms and sizes. In this article, we will look at the most common types of holes and the bits intended for them.

Straight slot (SL) - the most popular and simplest view slot. It is a straight slot through the center of the fastener head. The head for fasteners with a straight slot is called "slotted" or colloquially: "flat", "straight" or "minus". The working end of the screwdriver is a wedge-shaped plate.

The disadvantage of this slot is that due to the lack of clear centering, the screwdriver often flies out of the slot, while the edges of the slot itself "break", which is especially typical for high lingering forces. For this reason, a flat slot is poorly suited for assembling mechanisms and precision products.

Cross recess (PH) - a common type of hole in a fastener. The main varieties are the traditional Phillips and the more modern Posidrive.

Phillips (not to be confused with the Philips brand) is the oldest and most famous type of cross recess for threaded fasteners and screwdrivers or bits for them.

This slot was patented and launched into production by a certain H.F. Phillips, who, in turn, acquired the rights to the idea from the inventor J.P. Thompson.

In a cruciform slot, in comparison with a straight slot, the grip is strengthened, the moment of force on the axle is reduced, but nevertheless, with a "tight" entry into the material, additional efforts have to be made to hold the bit in the product.

Pozidrive type slot (PZ) - is an improved version of "Phillips", and is used in the production of wood screws and self-tapping screws. In mechanical engineering and metalworking, posidrive is used much less often. Hallmark splines are small additional grooves, offset by 45 degrees relative to the main axes. They provide a lot of stability and anti-spinning protection, although they don't completely solve it.

Pozidrive screwdrivers, when used, are not pushed out of the slot - a more stable grip is formed, which reduces wear on the bit and the part itself.

Square slotRobertson (SQ) - was first produced in 1908 by Canadian Robertson, who introduced it into production instead of a straight slot. Subsequently, he was in demand by Ford in his automotive industry until Robertson refused to sell him a license to manufacture and sell the spline, after which the sales project in the United States completely failed.

Now the design of a slotted clamp with a square working part is used for locksmith's tool heads and in fasteners. Robertson slot is designed for quick head change hand tool with high reliability.

Hexagonal slot (Hx) - view of the slot of threaded fasteners in the form of a regular hexagon. The angle between the sides is 120 degrees. The head of the fastener is usually cylindrical with a hex socket, and a screwdriver or hex head bit is used to work with hex slots.

Hexagon head screws are used in mechanical engineering, furniture, aviation and automotive industries.

Slot typeTorx (TX) - a type of slot in the form of a six-rayed star.

This spline is capable of transmitting high torque without deforming the bit and tool. Fasteners with TX slot are usually used in technology: cars, bicycles, brake systems, various prefabricated metal structures, hard drives computers, ATMs, consumer electronics and fuel equipment.

Due to the reduced radial load, tool and bit life is extended. This is achieved due to the fact that the angle between the edges is only 15 degrees. This geometry creates virtually no stress. Unlike cross profiles, TORX does not require the application of effort to bring the screws, and there is no slipping effect, which is common, for example, in a minus slot. Thus, the force transmitted through a given spline will be much greater under normal application forces.

Please note that there is a difference between the TORX and TORX PLUS slot: in fact, it is possible to screw the TORX PLUS screw with a TORX screwdriver, but this will lead to rapid wear of both the screwdriver and the slot itself.

TORX Tamper Resistant (TXH) prevents inadvertent screw removal. The only difference with conventional TORX® is the hole in the center of the bit and the small pin in the center of the screw.

Slot type 3VING denotes a special "three-blade" type of slot for threaded fasteners and screwdrivers for them. Keys and screwdrivers are marked 3 V or TW(Tri-Wing). Initially, the 3VING spline was used in the aerospace industry, in particular for the assembly of wide-body aircraft, but later it was used in other industries, for example, in the manufacture of electronic devices. This slot is also used in chargers manufactured by NOKIA.

Slot typeTORQ- SET denotes a special "four-blade" type of slot for threaded fasteners and screwdrivers for them. Keys and screwdrivers are marked 4 V or TS... The 4V slot is only used in the aerospace industry, although 4V screwdrivers are available commercially.

Slot typeONE- WAY(CL) - means special view slot of threaded fasteners and screwdrivers for them, provided only for tightening. When you try to unscrew the slot, the bit cam immediately pops out of the groove. However, there is a head capable of unscrewing the CL slot. If such a "pribluda" is not at hand, all that remains is to drill the screw or, having drilled two holes in it, unscrew the 2P with a bat. Fasteners with ONE-WAY slot can be used in in public places to protect structures from vandalism.

Secret type slot fork wrench (2P) - with two rectangular cams, also known as "snake eyes". The slot is not designed to transmit a high tightening torque, and the force is transmitted here only through two pins, which does not allow the screw to be overtightened.

This type is used in lift panels, in some waiting rooms, in the subway, as well as for tightening spikes in some types of shoes.

There is also a variation of the bit - with three pins, which, for example, is used in the clutches of melee weapons and firearms.

Round Head Hex Slot Type Hexagon Balldrive (HB) - allows you to reach hard-to-reach places at an angle of up to 25 degrees. Slides into recess quickly and completely and reduces edge break problems.

Slot typeSpline (SP) - slot in the form of a twelve-pointed star. The twisting force is evenly distributed over all the beams of the star, allowing a high torque to be transmitted.

So given view The slot is widely used in cylinder head twisting and other motor connections.

A feature of the SP type is a tight fit and maximum coincidence of the contours of the bit and the product, therefore, if dirt and dust particles get inside the bolt, the bit deviates from the axis and can cut off the inner edges of the product and its teeth.

Slot with triangular head (TR) - a type of secret slot used by railway, fire services, and also in radio electronics.

The design is an equilateral triangle. The slot is not designed to transmit high tightening torques due to its small area.

We all use self-tapping screws when working with wood. And, of course, everyone has more than one type of them in the coveted drawer on the shelf. And how could it be otherwise, because there are a great many of them on sale. Hardware stores offer a wide range of self-tapping screws in various shapes, sizes and purposes. It is not difficult for an experienced craftsman to navigate even in such a variety: he selects the appropriate diameter and length to the weight and size of the parts to be fastened. A black self-tapping screw with a horn-shaped head is bought for work on drywall, and a universal self-tapping screw for dowel fastening. The galvanized self-tapping screw will be used when internal works, and for outdoor, for example, for assembling a terrace - stainless steel, which will not leave brown traces of corrosion on the board. Everything is clear and simple here. However, there is one more parameter: the type of self-tapping slot. And here questions may arise: why are there so many of them, how do they differ, and which slot is better?

Let's take a look at the most popular splines.

A slot is a slot, a recess in the end surface of a self-tapping screw head, designed to transfer pressure and torque from a screwdriver or power tool attachment to the self-tapping screw body when screwing in. Some craftsmen are used to using the term "drive".

Straight slot - Slotted (abbreviated SL)

The first, back in the Middle Ages, appeared a straight slot - Slotted. It is extremely uncomfortable and a relic of the past. Judge for yourself: when tightening, it is very difficult to hold a bit or a screwdriver on a straight slot coaxially with the body of the self-tapping screw. As a result, the tool loses its adhesion to the hardware and slides off, while the equipment wears out, there are often chips on the surface of the attached parts, the master can be injured. An attempt to communicate an increased torque leads to a breakdown of the straight slot.

Slot SL

Phillips slot (abbreviated PH)

The invention of the Phillips cross recess in the 1930s was a real breakthrough. It became possible to position the tool tip strictly in the center of the slot, coaxial with the body of the hardware, so the tool now holds better, less often slips. The screw-in speed has increased, it became possible to carry out assembly-disassembly without breaking the slot. The Phillips slot protects the thread from breaking due to the structure of the slots tapering to the bottom: at the end of screwing in, when the maximum value of the twisting force is reached, the tool tip is pushed out of the slot. However, it is this pushing effect that imparts an additional load to the inclined walls inside the slot, contributing to their premature wear, and in order to increase the torque, significant forces must be expended pressing the tool against the self-tapping screw.

Slot PH

Cross recess - Pozidriv (abbreviated as PZ)

In the 60s, a modified version of the cruciform slot appeared - Pozidriv (abbreviated PZ). It has 4 additional beams radiating from the center. Unlike the trapezoidal slots on the Phillips spline, the Pozidriv slot is rectangular, which reduces the bit pushing force and makes it possible to increase the torque. But, again, the twisting speed must not be forgotten at the end of installation, so as not to disrupt the spline.

Slot PZ

Torx slot (abbreviated as TX)

This problem is solved by modern Torx slot. It has the shape of a six-pointed star, so the craftsmen are used to calling it the Star. V Everyday life you can find such concepts as an asterisk key, an asterisk screwdriver (or a torx key, a torx screwdriver). These are Torx wrenches and screwdrivers. When using a Torx sprocket, there is no need to limit torque at the end of screwing in. When working in confined spaces and hard-to-reach places, due to the use of a special torx bit (screwdriver attachment) Torx-Ball - sprockets with a spherical tip, installation at an angle to the axis of the self-tapping screw is possible. Unlike Phillips (PH and PZ), the torx sprocket is not clogged with paint and varnish after decorative protective treatment of the wood surface. Torx allows you to unscrew the self-tapping screw if necessary. The torx bit is in maximum contact with the head surface, slipping is excluded. Slot Torks has the most high degree transmission of torque from the tool to the installed self-tapping screw. It is not surprising that it is the Torx slot that is located on the heads of structural self-tapping screws (up to 600 mm long), which ensure reliable fixation of the most critical connections.

Torx size or number of torx varies depending on the diameter of the screws and screws.

Torx slot

Correspondence table of screw / self-tapping size and Torx number

So, we have found out that the TORX slot is the most productive and reliable - and these are exactly the qualities that are valuable for any professional.

And one more fact: on the shelves of construction hypermarkets of our northern neighbor - Finland - self-tapping screws and TORX screws became the most popular fasteners . For example, the popular self-tapping screws with a flange for thin metal sheets with a torx drive can be bought there for a long time. Torx wrenches, a torx screwdriver, a set of torxes for any need - all of these are also on sale.

We hope that sooner or later this trend will reach us.

Save time and energy! Buy TORX- perfect solution... Choose the best with CCI.

The screwdriver is universal tool, which is indispensable when you have to work with threaded fasteners of screws, self-tapping screws, screws. Usually we use only two screwdrivers at home - a flat and a Phillips screwdriver, as the most popular. But in fact, there are many types of them, it all depends on the slot with which you have to work.

A screwdriver is in some cases more convenient to use than a screwdriver. She doesn't need Electric Energy, the tool allows you to get to hard-to-reach places... And the screwdriver is much cheaper, so it perfectly replaces the screwdriver, unless, of course, you have to assemble furniture on a truly industrial scale or overhaul.

You can talk a lot about the types of screwdrivers, but it is much easier and clearer for you to imagine the following diagram:

Flat or straight slot is designated by letters SL... A well-known and very simple flat-slot screwdriver. A flat blade is used when working with the simplest fasteners, which are often found in fasteners for locking hinges, sockets, wooden shelves... It is widely used in everyday life.

Phillips - a Phillips screwdriver that is marked with letters PH... Excellent for most screws and self-tapping screws, is now the most common.

Marking PZ (Pozidriv) also used for Phillips screwdrivers, but with a deep slot and four smaller additional edges. Such tools are also widely used in the assembly of furniture, work with drywall, and the installation of various wooden structures.

Hex screwdriver marked with letters HEX... To work with a hexagonal slot, special high-torque screwdrivers are used. Their main difference is the rods bent in the shape of the letter "L". Hexagons are actively used in the repair of electrical equipment, as well as where you need to unscrew the fasteners on an energized object. Hexagonal slots with a pin in the center are called protected.

TORX. The slot is in the form of a hexagonal star. This is a fairly highly specialized screwdriver; in everyday life, such fasteners are rarely used. However, torcs are indispensable in service centers and various repair shops.

There is a variety of TORX splines with a pin in the center. They are called secure, Security T.

As you can see in our laughter, there are more varieties of screwdrivers, we have given only the most common options. There are highly specialized ones such as the Torq-Set with an asymmetric cruciform section. These splines, which allow the screw to be tightened powerfully, are used in the aviation industry.

Tri-Wing, or "trefoil", is needed where the connection must be reliably protected from self-unwinding, and the two-pin slot (spunner or Snake-eye) is used in public places, for example, in elevators, because it cannot be unscrewed with improvised means.

The size of the screwdriver will also be of great importance. The size is always indicated on the marking, but often this point is difficult to understand. DIY home craftsmen often just say - a flat screwdriver, large or small. Meanwhile, it will not be difficult to understand such markings:

• The number 0 implies that the diameter of the tool shaft is 4 millimeters and its length is up to 80 millimeters.
• Number 1 - the diameter of the rod is 5 millimeters, the length is up to 100 millimeters.
• Number 2 - diameter 6, length - up to 120 millimeters.
• Number 3 - 8 and up to 150 millimeters, respectively.
• Number 4 is the largest screwdriver, with a rod diameter of 10 millimeters and a length of up to 200 millimeters.

The marking itself is usually written like this: PH3 x 150mm. That is, a Phillips screwdriver, number three - a diameter of 8 millimeters, the length in this case is already indicated, but this is an optional parameter.

In addition, screwdrivers can have the following capabilities:

1. Dielectric coated screwdrivers will be very useful to electricians, which will protect against electric shock.
2. Also an option for electricians - a screwdriver with a device for detecting hidden wiring, as well as the presence in the socket electric current... Such instruments are also called probes and testers.
3. Screwdrivers with flexible shank, which are required for work in hard-to-reach places.
4. Ratchet reversible screwdrivers. They are needed in case of prolonged work with fasteners.
5. Rods with magnetized holders. They hold a self-tapping screw or screw, it is very convenient to work, especially with small fasteners.

Various sets of screwdrivers with replaceable nozzles... It is convenient that they do not take up much space; you can always choose an option for one or another slot. Screwdriver sets can be sold in suitcases or in such compact stands.

It’s pulled from Wikipedia, let it hang here, it won’t bother anyone, so I’m writing because I need to somehow collect all the information on the slots in one place in my head and put it on the shelves. Add-ons, srachi and more are welcome.

Everything is clear here.

SL indicating the width and (not always) the thickness of the slot in millimeters.

Cross recess (PHILLIPS and POZIDRIV)

Two types: Philips and Posidrive

Phillips: early version.

Screwdrivers are letter-marked PH with slot number - 000 (1.5 mm), 00 (2 mm), 0, 1, 2, 3, 4.
Varieties:
PHILLIPS II
ACR RIBBED PHILLIPS
PHILLIPS SQUARE-DRIV

Posidrive: a modern version.

Screwdrivers are letter-marked PZ with slot number - 0, 1, 2, 3, 4.

Varieties:
POZISQUARE DRIV
If you use screwdrivers to the wrong slot, the slot itself can be ripped off.

The head of the fastener is usually cylindrical with a hexagon socket. To work with splines of this type, use hex wrench(inbus key)

There is also Hex Tamper Resistant as a variant:

INBUS is an acronym for In nensechskantschraube B auer u nd S chaurte - Bauer & Schaurte socket head screw

Keys and screwdrivers are marked SW with a slot size in millimeters or fractions of an inch (distance between parallel edges):

Standard metric dimensions defined in ISO 2936: 2001
0.7; 0.9; 1.0; 1.25; 1.3 and 1.5
from 2 to 6 in 0.5 mm increments
from 7 to 22 in 1 mm increments
24, 25, 27, 30, 32, 36, 42 and 46 mm.

Torx (asterisk)

Torx - A type of slot of threaded fasteners in the form of a six-pointed star.

Varieties:
Torx Plus, the same eggs, current in profile and more square.

Torx Tamper Resistant (anti-vandal) with pin, TR marking

Brigadier Pentahedron key set - five-beam (no pictures found)
TORXSTEM the same shit with pictures

AudiTORX (ShkodaZvezdochka)

Well, any exotic:

Square (Robertson slot)

A square slot is a type of slot of threaded fasteners in the form of a regular square. Well, I’m not going to use it for technological holes in the automotive industry.

Heat and lamp, blaspheme still Soviet GOST

There is a chance of seeing a variant of the Square Tamper Resistant with a pin.

One-way (slot)

Anti-vandal, only for twisting.

Spanner

Two-pronged fork. Found in elevators

Used in Chevy and GMC
Two types:
A

Spline M-Profile(twelve beam star)

As they say specifically for Schkodochka (Volkswagen)

Tri-groove

Sobsno there are still them, but I wrote about those that I actually met in my life.

UPD. But I haven't written anything yet, but there is a chance of meeting:

Pentalobe

Oddly enough, everyone saw it for their love.

Nothing more than a slot on the core products.

Stellated octahedron

UPD. To help takc
FOUND!
In short, what is widespread from above is standardized in one way or another: there are both GOST and DIN, and in general. But then the Scandinians start to get ridiculous, since the oval head is used in Nescafe (Nespresso) and Ikea.

This is called: oval-head screws
Sold on Amazon (for coffee makers)

From improvised means, it is fixed as follows:
fitting it to the desired look

Proof (careful french mov)

Here's another version:

By turning bits from an aluminum rod.
With a plastic straw.

sic, here it is clear who is:

Well, just by gluing the tube to the bolt:

Who, can I introduce more tags? Kind of: cognitive and fixture?

Srach, improvements, govnometaniya and other joys of life are welcome. Additions to the text and corrections by the author are MANDATORY!