To screw a screw or self-tapping screw into a part you need bits, everyone knows about this. But, if you show an ignorant person bits for screwdrivers marked pz2 and ph2, few will be able to find the differences. After reading the article, you will learn not only the difference between PZ2 and PH2 bits, but also get an idea of ​​​​in what cases to use them.

PH2 bits: description, purpose

Until 1933, screwdrivers with a straight cut (flat) were used in production, which could easily damage parts, and they turned out to be unsuitable for mechanical tightening of screws. The invention of Phillips screws and the same bits was revolutionary. Henry Phillips bought the patent, and the bits began to be called after him - PH or Phillips. Depending on the size, a number from 0 to 3 is added to the marking. PH2 bits are used in everyday life, the features of which are:

• slot in the form of a cross with a bevel angle of 550;
• the ability to screw screws into soft or thin material;
• When working with a screwdriver, upon completion of tightening, the tip of the bit is pushed out.

Despite the apparent convenience, the main drawback quickly became apparent: the lack of strong adhesion to the surface, as a result of which the edges of the bit and screws “lick off.”

PZ2 bits: application and description

In 1966, Philips received a patent for screws and bits with an improved slot - PZ (posidriv). The difference between PH and PZ is the addition of additional edges located between the main four. A kind of “cross within a cross.” Numbers from 0 to 4 are added to the letter marking PZ, indicating the size of the bit. For domestic use, PZ2 is most often used.

Thanks to the additional edges, such bits provide a more reliable grip on the screw slot, so the parts are not damaged. You can work at any angle relative to the screw itself, with any torque. Most modern hardware used in everyday life are marked PZ2.

Conclusions

Let us summarize the difference between the PH2 and PZ2 bits. The first ones are designed for screwing screws into soft material and have only 4 edges. The second ones have 8 edges and are used to screw a self-tapping screw into a hard-to-reach place or into dense material.

It’s easy to understand which bit to choose for a particular piece of hardware: take a closer look at the head. If the groove for the bat has notched rays directed from the center to the edges, use a Podriv bat. Otherwise, use Phillips.

Bits for screwdrivers and screwdrivers: understanding the markings

Which bit will fit which screw? The most popular types and types of bits used in hand and power tools. Marking bits and their differences...

Since the advent of electric screwdrivers and hand-held screwdrivers with interchangeable attachments, the production of bits for unscrewing various fasteners has also begun to develop at an active pace.

At the moment, the industry produces a large number of varieties of bits. This article will highlight only the main, most popular types of these attachments.

A standard bit is a hex shank designed to be clamped into a chuck or held in an adapter; the shank, which goes into slots of different standards, is paired with a specific type of screws or self-tapping screws.

Types and types of bits

PH - (Phillips standard)

The PH standard is a Phillips spline with an apex angle of 55°. Each of the four splines has an extension towards the shank.

Bits marked PH can have different slot diameters and are marked from the small PH 0, designed for small diameter screws, to PH3, capable of holding large screws.

Bits marked PH 2 are the most common, as they are used for tightening so-called self-tapping screws for thin metal, or (black) self-tapping screws that have a simple cross-shaped slot in the head.

The PH standard is more universal and can be used with other screws.

PZ - (Pozidriv standard)

This standard is suitable for self-tapping screws that have slots in the Pozi standard head.

The Pozidriv standard is a kind of improved version of the previous type of bit.
PZ bit - represents a cross-shaped slot, having the same thickness of each edge with an apex angle of 50°.

A significant difference between the PZ bit is the “double cross”. The placement of additional small splines between the main splines made it possible to increase the holding force of the bits.

PZ standard bits are also available in different sizes and can be marked PZ1, PZ2, PZ3.
PZ standard bits are used for such self-tapping screws as UP (universal countersunk), which has an average thread pitch, as well as for other self-tapping screws with a Pozi slot.

SL - (Slot - Straight slot)

The well-known flat spline also has its own marking, such a bit is called SL.

The SL standard is a straight spline (flat), which can have different widths.

The width in millimeters is indicated after the SL marking - for example, SL 5, from which we understand that we are dealing with a bat that has a flat slot 5mm wide.

Torx - (Six-pointed star)

This slot, when viewed from the end of the bit, is a six-pointed star; the differences lie in the diameter of the star.

The slot number is indicated on the bit and comes after the inscription Torx or simply the letter T, for example Torx 10 - which corresponds to approximately 2.74 mm. Torx has its own numbers for different bit sizes.

Torx slots are used where high torque is required when tightening fasteners. Such a slot can be found on powerful self-tapping screws.

In addition to marking the slots, the bit may have a different shaft length or a limiter that will not allow you to turn the screw in the drywall further than necessary.

Material characteristics and bit coating

An important component when choosing a particular bat is the material from which it is made, as well as the coating that can withstand various influences.

On the construction market you can find bits from different manufacturers with a wide price range. The durability and ease of working with a bat depends on the grade of steel used for their production.

Probably the most common are bits with the steel marking Cr-v (chrome - vanadium), there are also bits made of chrome - molybdenum steel, etc. In addition to the composition of the steel itself, some bits are coated with a protective coating.

Manufacturers are competing for consumers and more and more new technologies are being used in the production of bits.

For example, a bit that has a nickel coating, on top of which a second chemical compound of tungsten carbide is applied, has increased corrosion resistance due to the nickel layer. And tungsten carbide, which is the outer shell, enhances the strength of the bit, which increases its service life even compared to a diamond-coated bit.

There are bits with a titanium coating, which gives the bit increased hardness and corrosion resistance.

Very often, especially in inexpensive sets, there are bits whose steel strength is highly questionable. Such a bit is usually enough to tighten several screws, after which its edges are torn off and the bit becomes useless. A low price for a bat is not always an indicator of poor quality; on the construction market you can also find decent examples at fairly affordable prices.

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Even in ancient times, when decorating the interior of buildings, people used the predecessors of modern ceramic tiles - thin flat bricks cut from natural stone, each of which had a pattern...

Well, since everything is so serious, then keep it:

The splines that serve to transmit torque from a tool (screwdriver, bits) to the screw itself have a very wide variety, some of the most common ones are shown in Fig. 3. The most traditional type of spline, straight, has recently been used less and less. A radical change in the development of spline designs occurred after the introduction by Phillips of a screw with a cross-head slot, which significantly simplified and accelerated the screwing process. Created for small fasteners used in instrument making, it turned out to be so attractive to consumers that it became widely used in a wide variety of fields. A further development of the cross-shaped spline was the Pozidrive spline, which is capable of transmitting greater torque due to a smaller apex angle, additional antennae and the absence of an inclination of the side working surface relative to the vertical plane (Fig. 2). This reduces the force pushing the tool out of the slot and makes it easier to apply torque, but when inserting a screwdriver (bit), more precise centering is required. Even greater forces are transmitted by the Torx slot, but when screwing screws en masse it is not very convenient (it is more difficult to combine the tool with the slot of the fastener), so this type of slot is used more often for powerful screws (frame, facade, self-tapping screws for concrete, dowels, etc. ). Square slots and internal hexagons are used quite rarely, for example, internal hexagons are used in specialized furniture screws - “Confirmat” ties.

Fig.3. Types of slots of screws and self-tapping screws

Each of the main types of splines also differs in size, creating a standardized and numbered row with a specific name. For example, Phillips splines are designated by sizes Ph1, Ph2, Ph3, Ph4, Pozidrive splines - Pz1, Pz2,..., Torx - T10, T15, T20,... Thus, a fairly large set of spline options is formed, which in turn requires and a corresponding set of tools for tightening screws.
For each type of slot and its number (size), a corresponding tool (screwdriver, bit) is required. At the same time, the common term “phillips” screwdriver does not stand up to criticism. The fact is that the angle at the top of the Phillips slot (and the corresponding screwdriver) is 55°, and that of the Pozidrive slot is 50°, so a screwdriver (bit) that does not correspond to the slot will not fit tightly into the recess in the head (see Fig. 4). In addition, the slope of the side working surface of the Phillips slot does not align with the almost vertical surface of the Pozidrive slot. As a result of the above, the working surface of the screwdriver-screw contact noticeably decreases, and with the same force, the contact stress increases both in the tool and in the screw head, which leads to increased wear or even destruction of one or another element. A similar effect occurs when the wrong size (number) of the tool is selected (Fig. 4).

Thus, for effective work, a consumer using various types and sizes of screws (self-tapping screws) requires an appropriate set of screwdrivers (bits).
In order to somewhat facilitate the consumer’s work in changing tools when changing screws, some manufacturers practice producing screws with combined splines (Fig. 3.), which allow working with such screws with two different types of tools. It should be said that the gain in making work easier is quite doubtful, and the losses in increasing the complexity of production (and, as a consequence, increasing the price) and often in the strength of the head are noticeable.
Figure 3 also shows examples of special splines (they are also called “with a secret”), their production and use are very limited and are of a singular nature.

In my childhood, the choice of tools was very limited - a hammer, a saw, a wrench, or better yet, a universal bicycle “family” wrench and two types of screwdrivers, flat and Phillips. Then it turned out that any of these instruments is divided into entire families of different instruments. Hammers come in light, heavy and sledgehammer types; with a sharp edge, chisel and nail puller; carpentry, joinery and geological; There are forged, cast, powdered metal, wood and even rubber. There are even special hammers for working in zero gravity that have no recoil! Saws were divided into dozens of types, tooth directions and for different tasks. And even wrenches, it turns out, come in not only open-end wrenches, but also socket wrenches, socket wrenches, combination wrenches, adjustable wrenches, adjustable wrenches, pipe wrenches, and what the hell! In general, life turned out to be much more difficult than I imagined =)

However, screwdrivers in my world have long stuck to the concepts of “phillips” and “flat head”. In various sets of screwdrivers that I found at different times, there were some inscriptions, such as PH or PZ - my brain somehow explained this to itself as foreign markings and I did not delve into these designations. But one day I suddenly understood the essence of these designations and, frankly speaking, I walked around for a week amazed at my insight!!! It seemed to me that this was some kind of secret knowledge that no one knew. The world of screwdrivers suddenly went from 2D to 3D!

Types of splines

First, a little about a flat-head screwdriver

Screwdrivers with a straight slot are marked with the letter SL, which stands for “Slot” and is literally translated as “Slot”. The number in the marking indicates nothing more than the width of the slot in millimeters. SL No. 6 is a 6mm wide flathead screwdriver - it's very simple. A straight slot is the first and simplest type of slot in threaded fasteners, known since the 15th century.

This slot is very simple to implement, however, during the times of scientific and technological progress during the mass assembly of cars and airplanes, it developed a serious drawback - due to the lack of clear centering, a screwdriver or screwdriver easily slips out of the slot, while the edges of the slot itself “break off” which is especially typical for high protracted forces, and the screwdriver leaves scratches on the part and the installer’s hands. In addition, such a slot allows for the transmission of a fairly large torque, which contributes to stripping the threads on the screws and breaking the screw heads themselves. For this reason, the flat spline is poorly suited for assembling mechanisms and precision products.

A moment of history

The flat slot did not immediately transform into a Phillips slot. There was also a transitional option. The first splines suitable for automated production were invented by Canadian Peter L. Robertson in 1908. The slot is patented under the name Robertson - a square cutout in the head with a chamfer on the edges and a cone-shaped recess in the center. The Robertson screw had a number of undeniable advantages: inexpensive to manufacture, allowing the screwdriver to be firmly centered in the square recess of the head, it made it possible to work almost with your eyes closed, by touch, at a minimal angle. The applied effort decreased in proportion to the increased productivity. For some time, these screws were used by Henry Ford in the production of the Ford T and Ford A models, saving 2 hours on assembly time! Given the mass assembly line, this was a phenomenal breakthrough. But Robretson did not want to give the rights to Ford, just as he did not want to license other screw manufacturers, so this slot did not gain popularity. Today they are used mainly only in Canada. By the way, Robertson is one of the best splines, and much better than Phillips.

Phillips PH

In 1933, American John Thompson developed screws that effectively solved the disadvantages of the flat spline. They automatically center the screwdriver blade and push it out when the screw is tightened. However, all his attempts to introduce his invention into factories led to nothing. The next year, chance brought him together with engineer Henry Phillips. He bought Thompson's patent and founded the Phillips Screw Company in 1936. Henry Phillips (who is not related to Gerard Phillips, the creator of the Philips brand of household appliances) developed the technology for producing such screws, but he also encountered difficulties in introducing his invention widely. Phillips actively sought out customers willing to buy his screwdrivers and screws, but was rejected after rejection. Meeting Eugene Clark, president of the American Screw Company (the company that was the largest manufacturer of hardware in the United States), radically changed the situation. Clark liked Phillips' invention so much that he allocated $500,000 to re-equip the production of his enterprise. Despite the objections of the company's top engineers, Clark threatened to "fire anyone who said it couldn't be done." We might not see any PH/PZ in our lives.

In 1937, General Motors pioneered the use of Phillips screws and screwdrivers in the production of Cadillac models. The results exceeded any expectations, and by 1940 all American automobile manufacturers had re-equipped their factories, and hardware manufacturers literally lined up to get a truly precious license to use the gold-bearing “cross.” During World War II, such screws began to be used in the production of military equipment.

It is noteworthy that it was the war that allowed Phillips screwdrivers and screws to spread throughout the world, and since then, manufacturers in all countries have been actively using them in the fastening industry. The “cross” came to Russia thanks to American B-29 long-range bombers. In 1944, these American planes, which bombed Manchukuo and Japan, made emergency landings in the Soviet Union. In accordance with the Russo-Japanese non-aggression pact, the bombers and their crews were forcibly left in the USSR. It was from them that the overseas screw was copied. This is how the Soviet Tu-4 appeared with a fundamentally new fastener for our country. The crusade of the updated screwdriver around the world ended with the global expansion of Phillips’ “cross”.

With such widespread adoption, Phillips Screw Company management was unable to track all the illegal uses of its patent, and the patent was canceled in 1949. And in 1958, at the age of 68, the inventor of the Phillips screwdriver himself, Henry Phillips, died, leaving behind an invention to the world that gave a significant impetus to the development of the entire world industry. A push that is not inferior in its significance to the invention of the conveyor belt. The name of the inventor of the Phillips screwdriver remains forever immortalized in the name of the Phillips slot.

Despite the fact that many experts today consider the Phillips cross to be outdated, it is still considered the de facto standard.

Advantages of the Phillips slot (PH)

Holds the fastener and screwdriver exactly centered relative to each other, compared to a conventional straight slot.

When using a screwdriver without adjusting the torque value, its tip is pushed out of the slot of the fastener when the maximum torque value is reached to avoid damage to the thread.

Disadvantages of the Phillips slot (PH)

It is impossible to obtain a large torque without applying significant axial force (pressing the screwdriver against the fastener).

Self-ejection increases mechanical stress on the spline, which increases wear on the spline and the likelihood of its damage (the so-called “breakdown”).

Phillips slot PZ

This spline was patented in 1966 by the same Phillips Screw Company, 33 years after it received a patent for the Phillips spline, which had expired by that time. PZ stands for POZIDRIV. Pozydrive is an improved version of the Phillips cross-head and is used primarily in the production of screws and self-tapping screws. In mechanical engineering and metalworking, Pozidrive is used much less frequently. Unlike the previously invented Phillips slot, the deep edges of the side surfaces of the Pozidriv screwdriver do not become thinner, but run parallel to each other. In this case, the axial force pushing the screwdriver out of the slot is insignificant - the screwdriver is practically not pushed out - a more stable grip is formed, which reduces the wear of the mating elements and the likelihood of the screwdriver slot and the fastener breaking off. It also becomes possible to apply more torque to the tool.

Advantages of the Pozydrive (PZ) slot

Reduced spline wear due to more stable grip.

Possibility of achieving high torque.

Disadvantages of the Pozydrive (PZ) slot

External resemblance to a Phillips slot - because of this, they can be easily confused and when using a screwdriver that does not match the slot of the fastener, incomplete contact of the working surfaces occurs - this significantly increases the mechanical stress on individual sections of the splines, leading to their premature wear (mainly in screwdrivers) or damage.

The slot is significantly deeper than Phillips, so it is used only where screws have large heads for reasons of strength - in construction and furniture production.

Size range of bits and screwdrivers

Screwdrivers with PH slots have numbers: 000 (1.5 mm), 00 (2 mm), 0, 1, 2, 3, 4.

Screwdrivers with PZ slots have numbers: 0, 1, 2, 3, 4.

The international standard for Phillips splines is ISO 4757:1983 (our GOST 10753-86). The screwdriver standard for it: ISO 8764-1:2004 (GOST R 52785-2007 “Pipe screwdrivers for screws and cross-head screws”), however, it does not describe sizes smaller than 0 (such as PH000 and PH00).

How to identify a bit type

Besides the fact that almost all bits and screwdrivers have markings, it is not difficult to visually distinguish these two types. PZ bits have additional rays running in the middle between the working splines. This design feature immediately catches your eye, unless the bit has a number lower than PZ1. In the PZ0 and sometimes PZ1 bits these rays are not expressed. If you look closely at the edges of the bit, you can see that the PZ bits have parallel slot edges, while the PH bits have trapezoidal edges.

Accordingly, the heads of the PZ screws also have diagonal rays. And sometimes there’s also a stamped letter Z for added significance.

Varieties

“The further into the forest, the more firewood” - this proverb can confidently be applied to screws! Phillips screws, at the time of their invention, solved the disadvantages of straight splines. Firstly, the screwdriver installed in the recess did not fly off when rotating. Secondly, when a certain force was reached, the screwdriver was pushed out of the screw, thanks to the rounded internal corners of the slot. Now this seems like a very stupid idea, but at that time the tool was bulky, and adjusting the torque was unthinkable, so it was the only way to prevent thread breakage during installation.

In general, all of today's attempts by manufacturers such as laser notches, ribbed surfaces, diamond or carbide coating, etc. This is just an attempt to at least somehow compensate for the initially inherent technological feature of Phillips splines. This happens when a flaw gains popularity too quickly and others are forced to adapt.

In addition to trying to improve Phillips, more than a dozen different Phillips splines were invented. Half of them are owned by the Phillips Screw Company itself. And almost all of them are designed to minimize push-out and improve torque transfer. If you try to cover all the varieties, you will have to write an encyclopedia of slots! But within the main topic, we will consider the directions for improving PH and PZ splines.

The Phillips slot currently has three varieties, in addition to its original state:

Phillips II is an improved version of Phillihps. Cross-shaped slot with inclined notches against ejection (ACR technology - anti-cam-out recess; distinctive marking - ACR2). Designed to meet increasingly fast assembly processes that may cause the screwdriver to be ejected from the screw, resulting in damage to the surface of the part. It facilitates tightening in difficult installation positions and reduces pressure on the spline, resulting in reduced worker fatigue. Screw heads with such a slot have characteristic double notches along one of the diagonals, but are quite compatible with regular PH.

ACR RIBBED PHILLIPS- Cross-shaped slot with notches perpendicular to the axis of rotation. (Distinctive marking - ACR, anti-cam-out recess). The manufacturer emphasizes that this bit reliably holds the screw on the blade of the screwdriver, which increases worker productivity. This bit is compatible with all Phillips screws and the screw heads are no different from regular PH. In the photo on the left, the two bottom elongated bits labeled S2 PH1 and S2 PH0 are ACR bits, the top ones are regular PH. Now almost all PH ACR bits are already in stores, i.e. with notches.

PHILLIPS SQUARE-DRIV - Phillips combination with a square drive. Cross slot with serrations (ACR technology), combined with a square slot. (Distinctive marking - PSD - PHILLIPS SQUARE-DRIV). Allows significantly higher torque. Just three screwdriver sizes cover the most popular size ranges. The screw heads have a double notch in one diagonal and a single notch in the other. The manufacturer claims that this bit/screw pair can be installed and tightened with one hand. The screw sits so tightly on the screwdriver that it is practically impossible for it to fall. Moreover, these are non-magnetic bits! The screwdriver is not compatible with regular PH screws, but PSD screws can be unscrewed with a regular screwdriver.

The Pozidriv spline itself is improved compared to Phillips, however, this spline also has one variety:

POZISQUARE-DRIV is a combination of the classic Pozidriv with a square slot. Perhaps the manufacturer made a typo somewhere in the description, but this bit looks and is marked exactly the same as the PSD. In general, the advantages of this slot are similar: it allows for significantly greater torque, holds the screw perfectly on the bit, and reduces worker fatigue. But, in addition, it is compatible with Canadian square screw systems!

Frearson (Fr)

PH and PZ are not the only Phillips splines. There was also Frearson - a rather rare and almost forgotten type of slot. Also known as Reed & Prince. Similar to Phillips, but has a sharp end and a larger V-shape angle (75°). One advantage over Phillips is that one screwdriver fits all screw sizes. Found in imported marine equipment. The lack of fillets on the cross slot allows for more force to be applied, unlike the rounded conical Phillips shapes that were designed to push the tool out at high torque. This spline was developed by English inventor Frearson in the 19th century and was produced from the late 1930s to the mid-1970s. In 1987 the company went bankrupt.

Phillips S

Specifications and standards do not apply to splines smaller than No. 0, however, there are a great many tiny screws in modern equipment. Especially in Japanese. That is why the Japanese have supplemented their spline standard (JIS B 1012) with size S. This type of spline is used for screws with a diameter of up to M2 and, if the screw head is small, then no more than M3.

Type S differs from type PH, although externally it can be confused. Moreover, in Japan itself there are two standards defining S-type splines: the already mentioned JIS B 1012 and JCIS 8-70 (Japan Camera Industrial Standards - industrial standards for Japanese cameras). In fact, it is a cross with minimal rounding of the internal corners. The splines of both standards are almost the same, with the exception of a narrower tip, tighter tolerances for JCIS and another difference in the length of the working part of the splines. S slots are found in cameras and accessories, various small electronics, and radio-controlled helicopters. Thus, Japanese screwdrivers of standard size PH0 differ from screwdrivers according to the ISO or GOST standard, since they are made for their “native” S-type slot. In the photo on the left you can see that the heads of the S-type screws have more straight internal angles than those of the PH. The top picture is the battery compartment of a Japanese Canon EOS camera, the middle photo is the autofocus motor of the lens of a Japanese Olympus camera and the bottom photo is the battery compartment cover of a Chinese toy.

Probably in every home there are at least two screwdrivers - a Phillips and a flathead. For many people, this is enough to screw in or unscrew a screw once a year. But screwdrivers, like any tool, do not last forever, and when the time comes to choose new ones to replace the old ones, a person will be surprised and confused. It turns out there are not two or even two dozen types of screwdrivers; in a decent store they can have a whole section dedicated to them. How to choose a screwdriver that suits your needs, and most importantly, a high-quality screwdriver, and not get confused in their diversity? We will try to answer this question in our article.

Typically, a screwdriver consists of three parts: a handle, a shaft, and a tip. It is clear that the strength of a screwdriver is determined by the reliability of its weakest link.

Tip (sting)

The shape of the screwdriver tip should match the shape of the slot - the groove on the head of the screw or screw. Previously, the most common was a straight slot, but now fasteners with it are becoming increasingly difficult to find, which is why not many straight screwdrivers are produced.

Now the most common is the Phillips slot (also called Phillips). There is also an improved version called Pozidriv. Such slots allow you to achieve greater torque, and the screwdriver tip does not fall out of them as easily as from a straight slot.

There are also hex splines and Torx splines (six-pointed star). They are designed for even greater loads.

Other types of slots can be classified as rare, and we advise you to buy screwdrivers with the appropriate tip shape only if necessary.

In addition to the shape of the tip, you need to pay attention to its size. Ideally, a specific tip size should be used for a specific slot size. Many people ignore this instruction and consider, say, a Phillips screwdriver to be universal, suitable for any Phillips slot. If you choose the wrong tip size and shape, you can break the tool or cut off the slot.

How to choose screwdriver size:

• Flat-head screwdrivers are marked with the Latin letters SL, followed by the width of the slot in millimeters. The width of a flat-head screwdriver can be from 2 to 18 mm; as its width increases, the thickness of the tip also increases. For most everyday tasks, the average user can get by with three flat-head screwdrivers of different sizes, say SL3, SL5 and SL8.
• Phillips screwdrivers are marked with PH symbols with a serial number (000; 00; 0; 1; 2; 3; 4). The most popular screwdrivers are PH2 size; they are suitable for most self-tapping screws and self-tapping screws used in everyday life.

The tip of the screwdriver must not only have the appropriate shape and size, it must be strong, hard, not brittle, and securely fixed in the slot. Achieving strength characteristics is facilitated by high-quality rod material and proper heat treatment.

In order for the tip to be securely fixed in the slot, it must be rough. The tips of high-quality screwdrivers are coated with a special coating with a high coefficient of friction, or notches are applied to its edges.

Kernel

Screwdriver shafts can vary in length, diameter, shape and strength. The strength characteristics of a rod are characterized by its hardness. According to GOST, it should be in the range of 47-52 HRC. If the hardness is lower, the rod may bend, if higher, it may crack. It is possible to ensure satisfactory hardness by using high-alloy chrome-vanadium steel, in which case the rod may be written “CR-V” or “chrome-vanadium”. But such an inscription does not always guarantee quality, because it is not difficult for unscrupulous manufacturers to apply it. Conversely, famous manufacturers do not always write what, in their opinion, goes without saying. To ensure corrosion resistance, various protective coatings are sometimes applied to the rods. Sometimes the rods are covered with rubber or plastic, this makes the work of electricians easier, but it makes the rod thicker than the tip, so it is not always possible to reach the head of the fastener, which is deeply recessed into the part.

The length of the rod is usually 100-200 mm. For working in tight spaces, screwdrivers with a short shaft and a shortened handle are produced. If the fastener is located in a hard-to-reach place, it is more advisable to use a screwdriver with a long shaft and take a telescopic screwdriver with an adjustable extension of the shaft.

The diameter of the rod depends on the size of the tip and the loads for which the tool is designed. The cross-section of the rod can be not only round, but also hexagonal or square. This shape allows you to grip the rod with a wrench and provide more torque.

We must not forget that the rod must not only be durable, it must be securely fixed in the handle. This factor cannot be controlled visually, so unscrupulous manufacturers often pay insufficient attention to fixing the rod, and over time it begins to rotate. You can safely throw away such a screwdriver, because it will not be possible to revive it.

Sometimes the screwdriver shaft extends through the entire handle and ends at a heel that can be struck with a hammer. This screwdriver will come in handy if you need to unscrew a screw with a painted slot.

Handle

Screwdriver handles are made from various materials, such as plastic, wood, and may have rubber inserts.

The dimensions of the handle must be selected based on the working conditions. If you have to work in cramped conditions, a short handle is better. Its diameter is almost always proportional to the size of the tip and the diameter of the rod. That is, the more powerful the fastener a tool is designed for, the greater the torque required and the thicker the handle should be. For screwdrivers for small fasteners, the handles are deliberately made thinner so that there is no risk of cutting off the slot or destroying the part into which the fastener is screwed.

The handles of modern screwdrivers can come in a variety of shapes; often manufacturers are guided not only by ergonomics, but also try to somehow distinguish their product from others due to the shape of the handle, sometimes sacrificing convenience. Therefore, when choosing a screwdriver, we recommend that you hold it in your hands.

The handle of a screwdriver can be not only cylindrical; there are T-shaped handles or pistol-type handles. They provide more torque, but make the tool less compact.

The handles of most screwdrivers are made of plastic with rubber inserts. For everyday tasks, this combination is ideal, but for work in contact with aggressive environments, it is advisable to opt for a material that is more resistant to their influence, such as plastic or wood.

On the back of some handles there are metal sockets for a wrench - not an absolute necessity, but in some cases a very useful feature.

It is advisable that there is a hole in the handle, so the screwdriver can be hung on a hook or a cord can be pulled through it and hung around the neck.

Additional features

The shaft of some screwdrivers can be replaced by a flexible shaft or equipped with a hinge, thanks to which you can screw the screw into a place where a regular screwdriver cannot reach.

There are also screwdrivers with ratchet. Thanks to the ratchet, free rotation of the handle in one of the directions is ensured, that is, you can screw in the fasteners without taking your hands off the handle.

Nowadays, screwdrivers with replaceable tips are increasingly common, which will satisfy the majority of ordinary users, but pros will bypass them, like any other “universal tool.”

Remember that you can only evaluate the quality of a screwdriver on a store counter visually. Therefore, all manufacturers (conscientious and not so conscientious) try to make their products look as attractive as possible. We advise you to only buy products from well-known brands.