We all use self-tapping screws when working with wood. And, of course, everyone has more than one type of them stored in a treasured box on their shelf. How could it be otherwise, because there are a great many of them on sale. Construction stores offer a wide range of self-tapping screws various forms, sizes and purposes. For an experienced master It’s not difficult to navigate even in such a variety: he selects the appropriate diameter and length to the weight and size of the parts being fastened. I buy a black self-tapping screw with a horn-shaped head for working on drywall, and a universal self-tapping screw for dowel fastening. Galvanized self-tapping screw will be used when internal works, and for external use, for example, for assembling a terrace - stainless steel, which will not leave brown traces of corrosion on the board. Everything here is clear and simple. However, there is one more parameter: the type of screw slot. And here questions may arise: why are there so many of them, how are they different, 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 the screw head, designed to transmit pressure and torque from a screwdriver or power tool attachment to the body of the screw when screwing. Some craftsmen are accustomed to using the term “drive”.

Straight slot - Slotted (abbreviated as SL)

The first, back in the Middle Ages, to appear was the straight slot - Slotted. It is extremely inconvenient and a relic of the past. Judge for yourself: when tightening, it is very difficult to hold the bit or screwdriver on the straight slot coaxially with the body of the screw. As a result, the tool loses adhesion to the hardware and slips, while the equipment wears out, chips on the surface of the attached parts are common, and the master can be injured. An attempt to impart increased torque results in the straight spline breaking off.

Spline SL

Phillips slot (abbreviated PH)

The invention of the Phillips cross-head slot in the 1930s was a real breakthrough. It has become possible to position the tip of the tool strictly in the center of the slot, coaxially with the body of the hardware, so the tool now holds better and slips less often. The screwing speed has increased, and it has become possible to perform installation and disassembly without breaking the slot. The Phillips slot protects the thread from breaking due to the structure of the slots, which taper towards the bottom: when screwing is completed, when the maximum value of the twisting force is reached, the tool tip is pushed out of the slot. However, it is precisely this pushing effect that imparts additional load to the inclined walls inside the slot, contributing to their premature wear, and in order to increase the torque, it is necessary to expend significant forces pressing the tool against the screw.

PH slot

Phillips slot - Pozidriv (abbreviated as PZ)

In the 60s, a modified version of the cross-shaped slot appeared - Pozidriv (abbreviated PZ). It has 4 additional rays diverging from the center. Unlike the trapezoidal slots on the Phillips slot, the Pozidriv slots have rectangular slots, which reduces the ejection force of the bit and makes it possible to increase torque. But, again, you must remember to reduce the twisting speed at the end of installation so as not to tear off the slot.

Spline PZ

Torx slot (abbreviated as TX)

This problem is solved by modern Torx slot. It has the shape of a six-pointed star, which is why craftsmen are accustomed to calling it the Asterisk. IN Everyday life you can come across such concepts as an asterisk wrench, an asterisk screwdriver (or a torx wrench, a torx screwdriver). These are keys and screwdrivers with Torx slots. When using a Torx sprocket, there is no need to limit the torque at the end of screwing. When working in confined spaces and hard-to-reach places, by using a special Torx bit (screwdriver attachment) Torx-Ball - sprockets with a ball-shaped tip, installation at an angle to the axis of the screw is possible. Unlike cross-shaped splines (PH and PZ), the torx sprocket is not clogged with paint and varnish after decorative and protective treatment of the wood surface. Torx allows you to unscrew the screw without any problems if necessary. The torx bit makes maximum contact with the surface of the head, slipping is eliminated. The Torx slot has the highest degree of torque transmission 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 screws (up to 600 mm long), which ensure reliable fixation of the most critical connections.

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

Torx slot

Correspondence table between screw/screw size and Torx number

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

And one more fact: on the shelves of construction hypermarkets in our northern neighbor - Finland - the most popular fasteners are self-tapping screws and TORX screws . For example, popular self-tapping screws with a flange for thin metal sheets with a torx drive you can buy there for a long time. Torx keys, a Torx screwdriver, a set of Torx bits for any need - all this is also on sale.

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

Save your energy and time! Buy TORX- perfect solution. Choose the best from TsKI.

ISO 10664-2007 - star socket for bolts and screws. Everyday names are star, asterisk, torx.

Story

The spline was developed by Textron in 1967. The use of tight-fitting bolts and bolts of increased strength class allows increasing the load on the fasteners; accordingly, a slot was needed, which provides a higher tightening torque. However, the unpopularity of the Torx tool made it possible to use the slot also to protect devices from self-repair owners. When the tool became popular, Textron added the new kind slot as a vandal-proof version of Torx.

In 1990, when the patent expired, Textron developed new standard Torx Plus is even more reliable and also has an anti-vandal option.

Varieties

• Torx External. Designated as E. It is an inverted Torx - the fastener has a star-shaped head, and the tool has a corresponding recess. Typically used in cars to reduce the size of a bolt head. There is no such thing as anti-vandalism. Available in sizes E4 to E44. The size numbering does not correspond to a regular Torx - for example, an E4 key will fit a T20 bit.
• Torx Tamper Resistant (anti-vandal) is designated as TR. In the middle of the slot there is a pin and a hole corresponding to this pin in a screwdriver or key. Other names: Security Torx, pin-in Torx.

• Five-spoke Torx. One of the anti-vandal options. Found under the names 5-lobe Torx, Brigadier Pentahedron key set, sometimes Pentalobe, which is incorrect, since Pentalobe is a separate daisy-shaped slot used in Apple electronics.
• Torx Plus. Improved spline with cut off ends of the star. Designated as IP (Internal Plus), it comes in sizes from 1IP to 100IP (sometimes labeled as IP1-IP100). Partially compatible with Torx - the Torx Plus tool can work with Torx fasteners, but does not provide maximum torque. Torx tools cannot work with Torx Plus fasteners.
• Torx Plus External. External Torx Plus option. Designated as EP (External Plus), it comes in sizes from 1EP to 42EP (EP1-EP42). Also has mini variants from H7EP to H2EP.
• The anti-vandal version of Torx Plus has five arms and a pin in the center of the recess. The marking is not specified in the standard, but may appear as TS or IPR.

Markings and sizes

Keys and screwdrivers are marked T or TX with slot number - 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 27, 30, 40, 45, 50, 55, 60, 70, 80, 90, 100.

Slotted keys and screwdrivers Torx Tamper Resistant TR.

For keys and slotted screwdrivers Torx Plus the spline number is indicated first, and then instead of T or TX indicated by letters IP.

Slotted keys and screwdrivers Torx Plus Tamper Resistant after the main marking they are additionally indicated T.S..

The size is determined by the circumference described by the vertices of the tool sprocket (for the E-bolt version).

Approximate dimensions and tightening torques

Number	Size		Torque	~ E Torx
	inches	mm	N m
T1	0,031"	0,81	0,02 – 0,03
T2	0,036"	0,93	0,07 – 0,09
T3	0,046"	1,10	0,14 – 0,18
T4	0,050"	1,28	0,22 – 0,28
T5	0,055"	1,42	0,43 – 0,51
T5.5
T6	0,066"	1,70	0,75 – 0,90
T7	0,078"	1,99	1,4 – 1,7
T8	0,090"	2,31	2,2 – 2,6
T9	0,098"	2,50	2,8 – 3,4
T10	0,107"	2,74	3,7 – 4,5
T15	0,128"	3,27	6,4 – 7,7
T20	0,151"	3,86	10,5 – 12,7	E4
T25	0,173"	4,43	15,9 – 19	E5
T27	0,195"	4,99	22,5 – 26,9
T30	0,216"	5,52	31,1 – 37,4	E6
T35
T40	0,260"	6,65	54,1 – 65,1	E8
T45	0,306"	7,82	86 – 103,2
T47	GM-Style
T50	0,346"	8,83	132 – 158	E10
T55	0,440"	11,22	218 – 256	E12
T60	0,519"	13,25	379 – 445	E16
T70	0,610"	15,51	630 – 700	E18
T80	0,690"	17,54	943 – 1048	E20
T90	0,784"	19,92	1334 – 1483
T100	0,871"	22,13	1843 – 2048	E24

External Torx Spline Dimensions

Number	Size		Standard bolt
	inches	mm	SAE	metric
E4	0,15"	3,8	#6	M3
E5	0,18"	4,7	#8	M4
E6	0,22"	5,6	#10	M5
E7	0,24"	6,1
E8	0,29"	7,4	1/4"	M6 & M7
E10	0,36"	9,3	5/16"	M8
E12	0,43"	11,1	3/8"	M10 & M11
E14	0,50"	12,8	7/16"	M12
E16	0,57"	14,7	1/2"
E18	0,65"	16,6	9/16"	M14
E20	0,72"	18,4	5/8"	M16
E24	0,87"	22,1	3/4"	M18 & M20
E28			7/8"	M22
E32			1"	M24 & M27
E36			1-1/8"	M30
E40			1-1/4"	M33
E44			1-3/8"	M36

Usage

Fasteners with Torx slots are commonly used in technology: cars, bicycles, brake systems, various teams metal structures, computer hard drives, ATMs, consumer electronics and fuel equipment.

It is unknown whether this was done on purpose or not, but the Torx sizes correlate with the sizes of the inbus keys and allow you to unscrew the torn hex slot. When a slot is torn off, a Torx tool is driven into the hole formed and, with almost one hundred percent success, allows you to unscrew the torn bolt or screw.

It should be noted that when working with Torx, the following features must be taken into account:

• The tool must fit into the fastener fairly tightly. If the tool dangles in the slot, then most likely it is selected incorrectly. This is especially true not entirely standard sizes, for example, T47, which is common in cars, is almost always absent from Torx key sets and is selected as T45.
• The tool must fit fully into the slot. Given the initially tight fit, this often requires the use of an impact tool.

Failure to comply with these rules often leads to destruction of the bolt head and, as a result, to unfounded criticism of Torx.

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Notes

Excerpt describing Torx

The head of the column had already descended into the ravine. The collision was supposed to happen on this side of the descent...
The remnants of our regiment, which was in action, hastily formed and retreated to the right; from behind them, dispersing the stragglers, two battalions of the 6th Jaeger approached in order. They had not yet reached Bagration, but a heavy, ponderous step could already be heard, beating in step with the entire mass of people. From the left flank, walking closest to Bagration was the company commander, a round-faced, stately man with a stupid, happy expression on his face, the same one who ran out of the booth. He, apparently, was not thinking about anything at that moment, except that he would pass by his superiors like a charmer.
With a sporty complacency, he walked lightly on his muscular legs, as if he were swimming, stretching out without the slightest effort and distinguished by this lightness from the heavy step of the soldiers who followed his step. He carried a thin, narrow sword taken out at his foot (a bent sword that did not look like a weapon) and, looking first at his superiors, then back, without losing his step, he turned flexibly with his whole strong figure. It seemed that all the forces of his soul were aimed at getting past the authorities in the best possible way, and, feeling that he was doing this job well, he was happy. “Left... left... left...”, he seemed to say internally after every step, and according to this rhythm, with variously stern faces, a wall of soldier figures, weighed down with backpacks and guns, moved, as if each of these hundreds of soldiers was mentally saying, every step of the way: “ left... left... left...". The fat major, puffing and staggering, walked around the bush along the road; the lagging soldier, out of breath, with a frightened face for his malfunction, was catching up with the company at a trot; the cannonball, pressing the air, flew over the head of Prince Bagration and his retinue and to the beat: “left - left!” hit the column. “Close!” came the swaggering voice of the company commander. The soldiers circled around something in the place where the cannonball fell; an old cavalier, a flank non-commissioned officer, falling behind near the dead, caught up with his line, jumped, changed his foot, fell into step and looked back angrily. “Left... left... left...” seemed to be heard from behind the threatening silence and the monotonous sound of feet simultaneously hitting the ground.
- Well done, guys! - said Prince Bagration.
“For the sake of... wow wow wow wow!...” was heard through the ranks. The gloomy soldier walking on the left, shouting, looked back at Bagration with such an expression as if he was saying: “we know it ourselves”; the other, without looking back and as if afraid to have fun, with his mouth open, shouted and walked by.
They were ordered to stop and take off their backpacks.
Bagration rode around the ranks passing by and dismounted from his horse. He gave the Cossack the reins, took off and gave his cloak, straightened his legs and adjusted the cap on his head. The head of the French column, with officers in front, appeared from under the mountain.
"With God blessing!" Bagration said in a firm, audible voice, turned for a moment to the front and, slightly waving his arms, with the awkward step of a cavalryman, as if working, he walked forward along the uneven field. Prince Andrei felt that some kind of irresistible force draws him forward, and experiences great happiness. [Here occurred the attack about which Thiers says: “Les russes se conduisirent vaillamment, et chose rare a la guerre, on vit deux masses d"infanterie Mariecher resolument l"une contre l"autre sans qu"aucune des deux ceda avant d "etre abordee"; and Napoleon on the island of St. Helena said: "Quelques bataillons russes montrerent de l"intrepidite." [The Russians behaved valiantly, and a rare thing in war, two masses of infantry marched decisively against each other, and neither of the two yielded until the clash." Napoleon's words: [Several Russian battalions showed fearlessness.]
The French were already getting close; Already Prince Andrei, walking next to Bagration, clearly distinguished the baldrics, red epaulettes, even the faces of the French. (He clearly saw one old French officer, who, with twisted legs in boots, was hardly walking up the hill.) Prince Bagration did not give a new order and still walked silently in front of the ranks. Suddenly, one shot cracked between the French, another, a third... and smoke spread through all the disorganized enemy ranks and gunfire crackled. Several of our men fell, including the round-faced officer, who was walking so cheerfully and diligently. But at the same instant the first shot rang out, Bagration looked back and shouted: “Hurray!”
“Hurray aa aa!” a drawn-out scream echoed along our line and, overtaking Prince Bagration and each other, our people ran down the mountain in a discordant, but cheerful and animated crowd after the upset French.

The attack of the 6th Jaeger ensured the retreat of the right flank. In the center, the action of the forgotten battery of Tushin, who managed to light Shengraben, stopped the movement of the French. The French put out the fire, carried by the wind, and gave time to retreat. The retreat of the center through the ravine was hasty and noisy; however, the troops, retreating, did not mix up their commands. But the left flank, which was simultaneously attacked and bypassed by the superior forces of the French under the command of Lannes and which consisted of the Azov and Podolsk infantry and Pavlograd hussar regiments, was upset. Bagration sent Zherkov to the general of the left flank with orders to immediately retreat.
Zherkov smartly, without removing his hand from his cap, touched his horse and galloped off. But as soon as he drove away from Bagration, his strength failed him. An insurmountable fear came over him, and he could not go where it was dangerous.
Having approached the troops of the left flank, he did not go forward, where there was shooting, but began to look for the general and commanders where they could not be, and therefore did not convey the order.
The command of the left flank belonged by seniority to the regimental commander of the very regiment that was represented at Braunau by Kutuzov and in which Dolokhov served as a soldier. The command of the extreme left flank was assigned to the commander of the Pavlograd regiment, where Rostov served, as a result of which a misunderstanding occurred. Both commanders were very irritated against each other, and while things had been going on on the right flank for a long time and the French had already begun their offensive, both commanders were busy in negotiations that were intended to insult each other. The regiments, both cavalry and infantry, were very little prepared for the upcoming task. The people of the regiments, from soldier to general, did not expect battle and calmly went about peaceful affairs: feeding horses in the cavalry, collecting firewood in the infantry.
“He is, however, older than me in rank,” said the German, a hussar colonel, blushing and turning to the adjutant who had arrived, “then leave him to do as he wants.” I cannot sacrifice my hussars. Trumpeter! Play retreat!
But things were getting to a point in a hurry. The cannonade and shooting, merging, thundered on the right and in the center, and the French hoods of the Lannes riflemen had already passed the mill dam and lined up on this side in two rifle shots. The infantry colonel walked up to the horse with a trembling gait and, climbing onto it and becoming very straight and tall, rode to the Pavlograd commander. The regimental commanders gathered with polite bows and with hidden malice in their hearts.

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

Splines come in various shapes and sizes. In this article we will look at the most common types of holes and the bits intended for them.

Straight spline (SL) - the most popular and simplest form slot. It is a straight groove passing through the center of the head of the fastener. Head for fasteners with a straight spline is called “spline” or colloquial speech: “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 groove, while the edges of the slot itself “break off,” which is especially typical for high protracted forces. For this reason, the flat spline is poorly suited for assembling mechanisms and precision products.

Phillips slot (PH) - a widespread type of hole in a fastener. The main varieties are the traditional Phillips and the more modern Pozidrive.

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

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

In a cross-shaped slot, compared to a straight slot, the grip is strengthened, the moment of force on the axis is reduced, but still, with a “tight” entry into the material, additional efforts have to be made to hold the bit in the product.

Posidrive type slot (PZ) - is an improved version of Phillips, and is used in the production of screws and self-tapping screws for wood. In mechanical engineering and metalworking, posidrive is used much less frequently. Distinctive feature Splines are small additional recesses offset by 45 degrees relative to the main axes. They provide greater stability and protection against scrolling, although they do not completely solve it.

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

Square splineRobertson (S.Q.) - was first produced in 1908 by the Canadian Robertson, who introduced it into production instead of a straight spline. Subsequently, he was in demand by Ford in his automobile 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.

Nowadays, the design of a slotted clamp with a square-section working part is used for heads metalworking tools and in fasteners. Robertson spline designed for quick socket changes hand tools with high reliability.

Hexagon spline (HX) - type of slot of threaded fasteners in the shape of a regular hexagon. The angle between the sides is 120 degrees. The head of the fastener usually has cylindrical shape with a hexagonal socket; to work with hexagonal slots, use a screwdriver or a bit with a hexagonal head.

Hexagonal screws are used in the mechanical engineering, furniture, aviation and automotive industries.

Spline typeTorx (TX) - type of slot in the shape of a six-pointed star.

This spline is capable of transmitting high torque without deforming the bit or tool. TX slotted fasteners are commonly used in automotive applications, bicycles, brake systems, various prefabricated metal structures, computer hard drives, ATMs, consumer electronics, and fuel equipment.

Thanks 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 any effort to drive the screws, and there is no slipping effect, which is common, for example, in a negative slot. Thus, the force transmitted through this spline will be much greater under normal application force.

Please note that there is a difference between a TORX and a TORX PLUS slot: in fact, it is possible to screw a 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 unintentional screw removal. The only difference with regular TORX® is the hole in the center of the bit and the small pin in the center of the screw.

Spline type 3VING denotes a special “three-bladed” type of slot for threaded fasteners and screwdrivers for them. Keys and screwdrivers are marked 3 V or TW(Tri-Wing). The 3VING slot was originally used in the aerospace industry, particularly for the assembly of wide-body aircraft, but later became used in other types of production, for example in the manufacture of electronic devices. This slot is also used in NOKIA chargers.

Spline 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 T.S.. The 4V slot is used only in the aerospace industry, although 4V screwdrivers are commercially available.

Spline typeONE- WAY(CL) - denotes special type slot of threaded fasteners and screwdrivers for them, intended only for tightening. When you try to unscrew the slot, the bit cam immediately pops out of the groove. However, there is a socket that can unscrew the CL spline. If such a “stray” is not at hand, all that remains is to drill out a screw or, after drilling two holes in it, unscrew it with a 2P bat. ONE-WAY slotted fasteners can be used in in public places to protect structures from vandalism.

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

This type is used in elevator panels, in some waiting rooms, in subways, and also for tightening cleats in some types of shoes.

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

Round head hex type Hexagon Balldrive (HB)- allows you to reach hard-to-reach places at an angle of up to 25 degrees. They are quickly and completely inserted into the recess and reduce the problem of “breaking” edges.

Spline typeSpline (SP) - slot in the form of a twelve-pointed star. The tightening force is evenly distributed across all rays of the star, providing the ability to transmit a high tightening torque.

Therefore, this type of spline is widely used when tightening cylinder heads 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 inner edges products and their teeth.

Triangular head slot (TR) - a type of security slot used by railways, fire services, and also in radio electronics.

The design is an equilateral triangle. The spline is not designed to transmit high torque due to its small area.

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

In some cases, a screwdriver is 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 a screwdriver is much cheaper, so it perfectly replaces a screwdriver, unless, of course, you are assembling furniture on a truly industrial scale or doing major repairs.

We can talk a lot about the types of screwdrivers, but it’s much easier and clearer for you to imagine this diagram:

Flat or straight spline is indicated by letters SL. A well-known and very simple screwdriver for flat spline. A flat blade is used when working with simple fasteners, which are often found in fastenings of lock hinges, sockets, wooden shelves. Widely used in everyday life.

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

Marking PZ (Pozidriv) also used for Phillips screwdrivers, but with a deep slot and four additional smaller edges. Such tools are also quite widely used when assembling furniture, working with drywall, and installing various wooden structures.

Hex screwdriver is marked with letters HEX. To work with hexagonal slots, special screwdrivers with high torque 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 it is necessary to unscrew fasteners on a live object. Hexagonal splines with a pin in the center are usually called protected.

TORX. Hexagonal star slot. This is a fairly highly specialized screwdriver; such fasteners are rarely used in everyday life. However, Torxes are indispensable in service centers and various repair shops.

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

As you can see from our laugh, there are more varieties of screwdrivers; we have given only the most common options. There are highly specialized ones, such as Torq-Set with an asymmetrical cross-section. Such slots, which allow powerful tightening of the screw, are used in the aviation industry.

Tri-Wing, or “trefoil”, is needed where the connection must be reliably protected from unwinding on its own, and a two-pin slot (spanner 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 label, but it is often difficult to figure out this point. Amateur home craftsmen often simply say - a large or small flat-head screwdriver. Meanwhile, understanding such markings will not be difficult:

• The number 0 means that the tool shaft diameter is 4 millimeters and its length is up to 80 millimeters.
• Number 1 - rod diameter 5 millimeters, length - up to 100 millimeters.
• Number 2 - diameter 6, length - up to 120 millimeters.
• Number 3 - 8 and up to 150 millimeters, respectively.
• Number 4 - the largest screwdrivers, have a shaft 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 - diameter 8 millimeters, the length in this case is already indicated, but this is an optional parameter.

In addition, screwdrivers can be equipped with the following capabilities:

1. Screwdrivers with a dielectric coating are very useful for electricians, as they 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 outlet electric current. Such tools are also called probes and testers.
3. Screwdrivers with flexible shafts, which are required for working in hard-to-reach places.
4. Reversible screwdrivers with ratchet mechanism. They are needed in case of prolonged work with fasteners.
5. Rods with magnetized holders. They hold a self-tapping screw or screw and are very convenient to work with, especially with small fasteners.

Nowadays you can purchase various sets of screwdrivers with interchangeable bits. It’s convenient that they don’t take up much space; you can always choose an option for a particular slot. Sets of screwdrivers can be sold in suitcases or in such compact stands.

Screwdrivers are basic tools for assembling/disassembling various technical mechanisms and devices. They are used to turn screws with special grooves various types on the heads (twisting and unscrewing) . The screwdriver increases and transmits the rotational movements of the hand to a small, specially sharpened working part (slot), which is inserted into the head of the screw. Typically, a screwdriver consists of two parts: a handle on one side and a slot on the other. Instead of a handle, a similar function can be performed by a rotating mechanism with an electric drive to facilitate the task of the person working with the tool. Electric screwdrivers have become one of the popular types of power tools.

The most important thing when using screwdrivers is to choose the correct type and size of tip to match the screw head. Never use screwdrivers that are not designed to handle the specific type of screw.

There are a great many different types of screws, and, in addition to using the traditional slot type, new types and screwdrivers for them are periodically invented. Most common types of screwdrivers, such as flathead and Phillips, have an extremely wide range of applications. At the same time, less typical species are used quite often in certain areas. Some screwdrivers are designed for servicing mobile devices (phones, smartphones, MP3 players, etc.). Often, manufacturers of electronic devices nowadays use special star-shaped screws, patented under the names Torx and Pentalobe.

We'll take a closer look at the most commonly used types of screws and the appropriate screwdrivers for them.

Spline types

Flat

The original and most commonly used type of screw is one that has a single slot in the head. However, this type of fastening is losing popularity because it is the least reliable - the screwdriver often slips out of the slot and the chances of damaging the screw or screwdriver are very high.

Standard marking: SL.

Cross Phillips

Another extremely popular type of spline is the Phillips spline. Phillips slot sizes (different from screw sizes) are designated 0000, 000, 00, 0, 1, 2, 3, and 4 (in ascending order of size).

Standard marking: PH.

Cross-shaped Pozidriv ®

The pattern is similar to a Phillips cross, but has 4 additional guides. Type of screws popular in Europe. Pozidriv sizes are similar to Phillips sizes.

Standard marking: PZ.

Star Torx

A six-point screw with a head hole in the form of a six-pointed star with rounded ends. A popular type of mount in electronics, automotive systems and other applications. Torx screw sizes are designated T1, T2 (or T01, T02) ... T55.

Standard marking: T.

Star-shaped Torx with anti-vandal protection

Anti-vandal Torx screw with additional protection Anti-tamper designed for applications where user intervention is not desired. Screwdrivers and wrenches for Tamper-proof Torx screws can also be used to work with regular Torx screws.

Standard marking: TxH, where x is the size.

Hex Hex

A screw with a hexagon-shaped hole that can be removed with a hex wrench or screwdriver.

Standard marking: H.

Also known as a triangular slot, it is a screw with three flat “wings” and a small triangular hole in the center. There is no specific use for Tri-wing bindings. They were once used in Nintendo products. Today, they are commonly used in electronic equipment. Tri-wing sizes are designated TRI000, TRI00, TRI0, TRI1, TRI2, TRI3, etc.

Standard marking: TRI.

Two-pin (spanner)

Screw with two round holes opposite each other is designed to avoid unauthorized access. Mainly used in electronics, public places: restrooms, elevators, train cars, etc.

Standard marking: SP.

External types

There are also several external types of screws for box screwdrivers - female screwdriver and male screw: square, pentagon, hexagon.

The most popular type of union connections is the hexagon. You can work with it using an adjustable wrench.

Below is a table with the most commonly used screwdrivers. All screwdrivers in this series are made of Ni-Cr-Mo alloy with an oxide tip.

Model	Type	Size	Working length	Image
Pro"sKit 9SD-201A		3.0	75 mm
Pro"sKit 9SD-202A		5.0	75 mm
Pro"sKit 9SD-205A		3.0	100 mm
Pro"sKit 9SD-207A		6.0	100 mm
Pro"sKit 9SD-210A		5.0	100 mm
Pro"sKit 9SD-213A		6.0	150 mm
Pro"sKit 9SD-214A		6.0	200 mm
Pro"sKit 9SD-220A		6.0	40 mm
Pro"sKit 9SD-222A		8.0	150 mm
Pro"sKit 9SD-201B		#0	75 mm
Pro"sKit 9SD-202B		#1	75 mm
Pro"sKit 9SD-205B		#0	100 mm
Pro"sKit 9SD-207B		#2	100 mm
Pro"sKit 9SD-210B		#1	100 mm
Pro"sKit 9SD-213B		#2	150 mm
Pro"sKit 9SD-214B		#2	200 mm
Pro"sKit 9SD-216B		#1	150 mm
Pro"sKit 9SD-217B		#2	250 mm
Pro"sKit 9SD-220B		#2	40 mm
Pro"sKit 9SD-222B		#3	150 mm
Pro"sKit 9SD-200-T05H		T05H	50 mm
Pro"sKit 9SD-200-T06H		T06H	50 mm
Pro"sKit 9SD-200-T07H		T07H	50 mm
Pro"sKit 9SD-200-T08H		T08H	50 mm
Pro"sKit 9SD-200-T09H		T09H	50 mm
Pro"sKit 9SD-200-T10H		T10H	75 mm
Pro"sKit 9SD-200-T15H		T15H	75 mm

Precision screwdrivers

What is a precision screwdriver?

Screwdrivers with highly precise tips, specially sharpened to precisely fit small and extra-small screw heads, are called precision screwdrivers. This type of screwdriver is used for assembling/disassembling components when repairing small devices and gadgets such as watches, Cell phones, cameras, portable computer devices and tablet PCs, players, video games and other electronics.

Traditionally, precision screwdrivers and sets of such screwdrivers are used by craftsmen, a good set of screwdrivers is also a must-have for every workshop.
The range of precision screwdrivers always includes the most commonly used types and sizes: slotted, Phillips, torx, hex. For some precision work, we need screwdrivers for special screws: TriWing, Pozidriv, spanner, etc. Apple uses a special anti-vandal screw for its products, which can be unscrewed/tightened with a Pentalobe five-pointed star screwdriver.

Torx

Torx screws are quite popular for precision applications such as computer repair, mobile device repair, electronics repair, etc. Sizes: T1, T2 (or T01, T02) ... T55.

Standard marking: T.

“Five-point anti-vandal screws” is the name of the system used by Apple for its developments. Pentalobe screw sizes include TS1 (0.8mm, used in iPhone 4, iPhone 4S, iPhone 5, iPhone 5c, iPhone 5s, iPhone 6, iPhone 6 Plus, iPhone 6S, iPhone 6S Plus, iPhone SE, iPhone 7, iPhone 7 Plus, iPhone 8, iPhone 8 Plus, iPhone X), TS4 (1.2 mm, used in MacBook Air and MacBook Pro with Retina display), and TS5 (1.5 mm, used in the 2009 MacBook Pro battery).

Standard marking: TS.

Tri-Point screws are used in the manufacture of mobile devices, electronics, etc. Apple began using them in smartphones that were released after the iPhone 6, as well as in the Apple Watch.

Standard marking: TP/Y.

Users often prefer to use screwdrivers from Pro"sKit, which has developed a whole series of precision screwdrivers. You can choose the perfect kit for your needs. The Pro"sKit SD-081 series contains the most commonly used screwdriver types, as well as some specific types for various specialized applications . You can see the products in this series in the comparison table below.

Model	Type	Size	Working length	Image
Pro"sKit SD-081-S1		1.0	50 mm
Pro"sKit SD-081-S2		1.6	50 mm
Pro"sKit SD-081-S3		2.0	50 mm
Pro"sKit SD-081-S4		2.4	50 mm
Pro"sKit SD-081-S5		3.0	50 mm
Pro"sKit SD-081-S6		2.4	75 mm
Pro"sKit SD-081-S7		3.0	100 mm
Pro"sKit SD-081-S8		4.0	150 mm
Pro"sKit SD-081-P1		#000	50 mm
Pro"sKit SD-081-P2		#00	50 mm
Pro"sKit SD-081-P3		#0	50 mm
Pro"sKit SD-081-P4		#1	50 mm
Pro"sKit SD-081-P5		#0	75 mm
Pro"sKit SD-081-P6		#1	100 mm
Pro"sKit SD-081-P7		#1	150 mm
Pro"sKit SD-081-T1		T01	50 mm
Pro"sKit SD-081-T2		T02	50 mm
Pro"sKit SD-081-T3		T03	50 mm
Pro"sKit SD-081-T4		T04	50 mm
Pro"sKit SD-081-T5		T05	50 mm
Pro"sKit SD-081-T6		T06	50 mm
Pro"sKit SD-081-T7		T07	50 mm
Pro"sKit SD-081-T8		T08	50 mm
Pro"sKit SD-081-T9		T09	50 mm
Pro"sKit SD-081-T10		T10	50 mm
Pro"sKit SD-081-T15		T15	50 mm
Pro"sKit SD-081-T20		T20	50 mm
Pro"sKit SD-081-T5H		T05H	50 mm
Pro"sKit SD-081-T6H		T06H	50 mm
Pro"sKit SD-081-T7H		T07H	50 mm
Pro"sKit SD-081-T8H		T08H	50 mm
Pro"sKit SD-081-T9H		T09H	50 mm
Pro"sKit SD-081-T10H		T10H	50 mm
Pro"sKit SD-081-T15H		T15H	50 mm
Pro"sKit SD-081-T20H		T20H	50 mm
Pro"sKit SD-081-H1		H0.7	50 mm
Pro"sKit SD-081-H2		H0.9	50 mm
Pro"sKit SD-081-H3		H1.3	50 mm
Pro"sKit SD-081-H4		H1.5	50 mm
Pro"sKit SD-081-H5		H2.0	50 mm
Pro"sKit SD-081-H6		H2.5	50 mm
Pro"sKit SD-081-H7		H3.0	50 mm
Pro"sKit SD-081-M3		M3.0	72 mm
Pro"sKit SD-081-M3.5		M3.5	72 mm
Pro"sKit SD-081-M4		M4.0	72 mm
Pro"sKit SD-081-M4.5		M4.5	72 mm
Pro"sKit SD-081-M5		M5.0	72 mm