How to make a hairpin driver with your own hands video

Unscrewing and screwing threaded connections such as studs without a special tool presents serious difficulties due to the lack of a turnkey head.

To solve this problem, a specialized tool is used - a pin driver.

The most common option is one that looks like a socket head for working with bolts and nuts, however, there are other types, each of which has its own unique design that simplifies work in a given situation.

What is a stud gun?

A stud wrench (stud wrench) is a specialized tool for screwing in and unscrewing threaded rods.

A stud is a fastener in the form of a rod with threads on both ends. The stud is screwed into the product in one part, and a nut is screwed onto the second part. The design of the stud does not provide special surfaces for the barb (such as the heads of bolts or the faces of nuts) or other tools, which significantly complicates the procedure for screwing it in and out. As a result, you have to use special tools, which are called stud wrenches or simply stud wrenches.

To properly purchase a stud gun, you need to understand the existing types of this tool, their features and advantages.

Testing a pin driver

First test. The bolt, tightly clamped in a vice, rotates quite easily without additional leverage. I cleaned everything up again. A handle from an old cord brush came in handy. Such a tool should last a long time, because... the metal is good, and the teeth are subject to additional hardening.

But the purchased pin driver is of a different design. The teeth on the eccentric were crushed on the first pin. (not visible in the photo).

How to use a pin driver?

Working with a stud gun does not require any special knowledge, and the whole process is briefly as follows:

The tool is put on a pin.
The eccentric is pressed tightly against the fastener.
The tool is turned with an open-end or spanner wrench using a hexagon, or with a crank inserted into the square hole provided for it.

The direction of rotation depends on whether the fastener needs to be screwed in or out.

Some models of stud drivers are one-sided, that is, they can only be screwed in or out, while others can be screwed in or out.

When starting work, make sure that the eccentric presses the pin tightly.

The advantage of using pin drivers

Quite a large number of people today encounter difficulties when dismantling threaded fasteners (studs or bolts). If we talk about car service, this is most often associated with the repair of old cars, where some connection elements have not been unscrewed for decades. The advantages of using a special device are as follows:

with its help, in the vast majority of cases, it is possible to unscrew a bolt with a broken head without damaging the threads in the part;
the pin itself remains practically undamaged; after running with a die, it is suitable for reuse;
minimum time spent on work;
Made from high-quality steel, the tool is durable and durable;
in hard-to-reach places it is often more convenient to use a pin driver rather than improvised means.

Simply put, the tool makes work easier and faster. It's no secret that a broken, rusty bolt in the absence of special equipment can paralyze all car repair work. A poorly turned pin can cause the repair time to triple. Therefore, if the pin suddenly does not want to turn out of a place where its breakage could cause serious problems, it is better to use tools specially designed for this.

DIY hairpin driver. This design will help unscrew the studs

Have a good time everyone. In this article we will talk about such a tool as a pin driver. Many have encountered such a task as unscrewing a hairpin. Usually, many people do this with two nuts, but it also happens that the threads on the studs are broken, and in such cases there is also a way out, for example, you can weld the nut. But all this takes time, and with the help of such a tool it is done much easier and faster. So the hero of our article decided to make himself such an instrument. And to do this, he took a piece of round timber and first processed it on a lathe to the required dimensions (Diameter 30 mm, length 40 mm)

Then he will make holes in these places. And since the holes should not be in the center, the author will make substrates on one side for the workpiece.

After one hole was made, the author decided to make two more holes. One is 10 mm, the second is 8 mm.

Next, the author took a piece from the car’s steering rack. According to him, this is an excellent steel metal.

I also made the substrates and started processing.

The result is a blank for the second part.

I connected it to the first part, and turning the second part in the first, I made a mark. According to which in the future he will make a groove for the first part in this way.

Then the author will make a notch on the second part using a well-sharpened chisel. Since this part was machined from durable steel, before applying the notch, the author warms up the part well.

Next, he will make a square on the edge of this part so that he can put the key on for working with the tool.

At the end, the author hardened the part, assembled the tool, and began testing.

How to make a barbecue grill with a lifting mechanism

Thank you all very much! And see you again.

Production video:

Roller pin driver

One of the most simple in design and reliable tools. In general, it is a cylindrical body, inside of which there are three cylindrical rollers, between which spacer inserts can be additionally installed. The inner surface of the housing has a complex profile (triangular with rounded edges and corners, with ovoid elements, etc.), so the rollers, rolling inside the housing, can move closer and further from its central axis.

The roller pin driver works simply. The tool is put on a pin and turned using a wrench or wrench. When turning, the rollers roll over the pin and the inner surface of the body, which leads to jamming of the pin - now the force from the hand is transferred to it, which allows you to screw it in or out.

Keys for studs of this type are simple, reliable and convenient, but they have a significant drawback - each stud driver is made for a specific diameter of the stud. Only in this case is the necessary pressure of the rollers against the pin and its jamming when turning ensured. Therefore, to work with various studs, it is necessary to have a whole set of roller stud drivers.

Device and characteristics

The hairpin driver consists of a housing, inside of which there is a clamping mechanism for permanently fixing the tool on the hairpin.

Depending on the device, these can be like collet jaws, the principle of operation of which is similar to the chuck of a drill or screwdriver,

or a wheel (one or several) with notches that are clamped by an eccentric mechanism.

The tool is put on the fastener, fixed by the fastening mechanism, and then rotated.

In other words, the stud driver acts as a removable head for the stud, similar to a bolt.

Various models are made as an independent tool, or can act as equipment.

In the latter case, the body has a hexagon-shaped shank, or a hole for a tetrahedron driver.

The body of the pin driver has a one-piece (often by milling followed by heat treatment) or welded structure, the main elements are made of tool steel, and the clamping elements are usually hardened.

Chrome-molybdenum steel is often used for clamping rollers.

At the same time, a protective zinc, chrome or other coating is applied to the body.

Design features of the pin driver, principle of operation

The most famous design of this tool consists of a housing in which three rollers are located. Thanks to the complex inner surface of the body, when rotating, the rollers firmly clamp the stud, ensuring its turning even in difficult cases (fastening automobile manifolds, muffler elements and other places where the thread of the studs “sticks” to the hole of the part into which they are screwed). On the reverse side of the case, as a rule, there is a square hole for a standard size of ratchets (wrenches), as well as a hexagonal shape of the outer surface for holding with a wrench.

How to make a garden branch shredder with your own hands

The branches left behind after tree trimming are quite an inconvenient waste. Piled up in a heap, they take up a lot of space, and you can’t put the branches into the oven right away; it takes a long time to chop them with an ax. Making a fire and just burning it in the garden is a shame. A suitable option for a thrifty owner is to make a branch chopper with your own hands to process them into wood chips. And there will be a use for it - even burn it in a cauldron, or use it for compost. We are interested in the designs of homemade crushers, since the prices of factory units are not comparable with the volumes of wood processing in an ordinary private sector.

GOST

There is no separate GOST that defines the technical requirements for pin guns; however, this tool was defined in GOST 16436-70, introduced in 1971 and reissued in 1992.

Loads

Each model of stud driver, taking into account the material of manufacture and design, has its own maximum permissible load (MPL), exceeding which when unscrewing or screwing the studs will lead to breakage of the tool.

Manufacturers often keep a small supply of PDN.

For example, a stud driver for working with 10 mm studs, intended for repairing vehicles, has a maximum permissible load, usually 33 Nm.

Purpose of stud guns

Unscrewing studs can be done in various ways using a common tool, for example, the same pliers or using the locknut method.

The principle of operation of the pin driver

Device and characteristics

The hairpin driver consists of a housing, inside of which there is a clamping mechanism for permanently fixing the tool on the hairpin.

Depending on the device, these can be like collet jaws, the principle of operation of which is similar to the chuck of a drill or screwdriver,

or a wheel (one or several) with notches that are clamped by an eccentric mechanism.

In the latter case, the body has a hexagon-shaped shank, or a hole for a tetrahedron driver.

Material

Dimensions and weight of stud guns

Standard stud guns weigh between 100 and 600 grams, and their length averages 60 to 120 mm, depending on the design.

Such models are designed to work with fasteners of dimensions M4 – M19. There are also non-standard options, which are mainly made to order.

Large specimens are designed to work with studs of dimensions up to M180 and larger, weighing up to 15 kg.

As for the size of the connecting square for using a wrench, the most common are 1/2, 3/4 and 1/4 inches.

There is no separate GOST that defines the technical requirements for pin guns; however, this tool was defined in GOST 16436-70, introduced in 1971 and reissued in 1992.

Loads

Types of stud guns and their prices

The main problem when working with studs is to securely fix the tool on them, and therefore several methods are used in stud driver designs to solve this problem, which led to their division into several types:

Roller pin driver

Before work, the pin driver is put on the fastener and then turned.

On the reverse side for this purpose there is a hole in the form of a square, or a hexagon for an open-end wrench or a head.

Cost – from 300 rubles per piece.

For a high-quality set of 4 units you will have to pay from 2.5 thousand rubles.

Collet pin driver

The advantage of such models is the ability to work with one stud driver with fasteners of different sizes.

Cost – from 1 thousand rubles.

Eccentric

Hairpin wrench

With nut clamp

Hairpin extractor

The cost of the set is around 3 thousand rubles or more.

How to choose a stud gun?

What you need to know about stud guns?

How to use a pin driver?

Working with a stud gun does not require any special knowledge, and the whole process is briefly as follows:

The direction of rotation depends on whether the fastener needs to be screwed in or out.

Some models of stud drivers are one-sided, that is, they can only be screwed in or out, while others can be screwed in or out.

When starting work, make sure that the eccentric presses the pin tightly.

Manufacturers of stud guns

Among the manufacturers involved in the production of stud guns, the following are popular:

How to make a hairpin driver with your own hands?

Question for experts: 2109 how to unscrew the timing belt tensioner pin if the thread on it is torn off without welding.

Best regards, Kostya***

Best answers

There is such a thing called a stud puller, just for such cases.

Gas key 1-2 numbers. I have pin drivers for these purposes.

Special pullers are sold for turning out such studs.

drill a hole, then slowly hammer in a triangular file and use pliers or my 8mm wrench or another to unscrew it, if the pin under the face is broken off, and then two nuts and unscrew, you need to learn EVERYTHING

There is a special tool called a pin driver.

The threads are stripped on the head, not the stud. Remove the head and drill it out 12mm

You screw on the second nut and unscrew the first one. If the thread is faulty, then a stud is for sale. Yes, don’t forget, there is a key for the roller, so you use it to secure it.

There are special hairpin drivers, you put it on the hairpin and turn it with a wrench using a cone to clamp the hairpin and unscrew it to tighten it, put the hairpin driver on the other side. There are several types of stud guns, ask at your auto store.

Tap a suitable head onto the end of the stud. It will slightly bend the hexagon-shaped pin. Insert the knob and unscrew it by the head.

if a bolt, pin, etc. cannot be unscrewed by the statute of limitations, then there is such an old-fashioned trick (unless, of course, you don’t have a special tool at hand). We carefully hit the pin with a hammer (the blow must be strong); if everything is done correctly, the pin should come out without effort using pliers.

Without special tools, no way. And with him, if you're lucky. Weld the nut or drill it out. A miracle won't happen. There are people who use toilet gas keys to repair cars. The carburetor is repaired with a construction trowel. Mobile phones with a knife. The result is always the same. Well, you understand…

Use a file to make 2 edges opposite, if you don’t have a small gas wrench, place a flat file under the gas wrench; the normal method always helps

How to unscrew a hairpin: 25 effective ways and techniques

How to unscrew the pin?
Let's consider several methods, taking into account the condition of the stud and the available tool. How to unscrew a stud by its threaded part

If the stud is long enough and a threaded part for 2 or more nuts is available, then we use one of the following methods:

screw on the nut, screw the second one all the way into the first one (it is advisable to use tall nuts), then unscrew the stud with a mechanic’s tool (wrench or other);
use a special tool - a hairpin driver, suitable for the size of a hairpin or a universal one.

An eccentric pin driver is convenient and effective - the greater the force applied to it, the stronger it clamps the pin with the eccentric notch.

How to unscrew a stud if there is only thread available for 1 nut? In this case, at least 4 methods are available:

cut the nut on one side with a hacksaw (the direction of the cut is along the axis of the threaded part), screw it onto the stud, clamp it with a pipe wrench so tightly that the threaded part, choosing a gap in the cut, tightly grips the stud, direct the force in the direction of unscrewing;
screw the nut onto the thread, weld it to the stud (for example, with a semi-automatic welding machine) and unscrew it with a wrench (or a head with a knob);
screw the nut onto the thread, drill a recess in the end of the stud (approximately half the diameter of the stud), drive a TORX socket (E-profile, or another similar one with longitudinal ribs) into this recess and unscrew it by the shank of the socket (you can use your second hand to help with this) with an open-end or socket wrench applying force to the nut in addition to the main force on the torx);
Using a hacksaw for metal, make a cut at the end for a flat screwdriver, with which you can remove the pin.

In the screwdriver method, a large version or a power version with a T-handle is better suited for this purpose.

How to unscrew a hairpin by its smooth cylindrical part

If only the smooth part of the stud is accessible (for example, the threaded part is broken), then the following techniques are applicable;

clamp the cylindrical part in a suitable tool (pliers, a pipe wrench, a small vice, a clamp, or the like) and apply force in the direction of unscrewing;
weld a metal rod to the broken end by welding as a T-shaped handle;
put on a nut of a slightly larger diameter, weld it to the stud in a circle and unscrew it with a wrench;
use a square washer as thick as a nut or more, with an internal diameter the same size as the diameter of the cylindrical part of the stud (ideally, if the washer fits on the cylindrical part of the stud with interference), cut it on one side in the same way as the nut in the previous subsection, put it on the stud, clamp pipe wrench and unscrew;
use a die (the one used for cutting threads), turning the end of the pin to a square of the desired size;
use a pin driver;
Using a hacksaw for metal, make a cut at the end for a flat screwdriver, with which you can remove the pin.

In some cases, if possible, to enhance the impact, simultaneously with applying force to a screwdriver or wrench, you can use a second tool (pipe wrench, pliers, etc.), clamping them on the smooth side surface and acting in the direction of unscrewing.

How to unscrew a broken hairpin

If the pin is broken and there is no part protruding above the surface, then you can unscrew it in the following ways:

using a semi-automatic welding machine, gradually and carefully “build up” a couple of centimeters (if the end of the stud is within the reach of the welding wire) and then unscrew the “build up” using a clamping tool;
use a special tool - an extractor (looks like a tap, the working part is conical, the thread direction is opposite to the thread of the stud): align the protruding end of the stud with a file (or saw off evenly with a hacksaw), tap exactly in the center, drill a hole of the required diameter along the axis of the stud and depth (approximately 2/3 of the length of the working part of the extractor), insert the extractor and rotate with force until the pin is unscrewed;
preparation with drilling as in the previous method, only use a tap on the left thread of the stud (if the stud is in the right direction) - when the tap, cutting the thread, rests on the bottom of the drilled recess in the body of the stud, the fragment is often unscrewed;
drill out the center of the stud, choosing the diameter in such a way as not to touch the threaded part of the socket, and then remove the remaining metal of the stud;
Drill out the broken part of the stud and the threaded socket on a drilling machine or with a hand drill with a drill of a larger diameter for the repair stud.

Using the method of drilling a recess and driving a Torx tip into it carries the risk of strengthening the wedge in the threaded socket due to the expanding deformation of the stud walls. Taking into account possible complications, we will not recommend it in this situation, despite the fact that it can be used in a limited manner, with certain conditions.

Aligning the end of the stud can cause difficulty if the breakage occurs in depth. In this case, an end burr will provide invaluable help.

Another variation for the drilling method. You can use drills with a left-hand direction of rotation and an electric drill with a direction switch and speed control. When drilling at low speeds, the wedged threads loosen and, due to the left rotation of the drill, the rest of the stud easily moves out of place and comes out of the threaded socket.

Drilling is often wiser to do in several passes, from a small drill to larger ones, to the desired diameter.

How to unscrew a stuck hairpin

A soured pin must be unscrewed using additional tricks, both in terms of tools and in terms of methodology.

Apply several blows with a hammer to the end of the stud along its axis without damaging the edge of the thread;
apply several gentle blows from different sides to the side surfaces of the stud (at the same time screw a nut onto the threaded part to avoid damage), without allowing it to bend;
apply special penetrating compounds - WD-40, liquid key and their analogues, giving the necessary time in accordance with the instructions for these drugs from their manufacturer before attempting to unscrew;
use an extension to the hand tool to increase the applied force (a longer wrench or by placing a pipe of a suitable diameter on the rotating end of the hand tool;
When unscrewing a welded nut, use not an open-end wrench, but a Super Lock head, in which the force is applied not to the corners (edges), but to the planes;
instead of using physical force and hand tools, use an impact wrench (if you don’t have one in your home workshop, you can go to the nearest tire shop or car service center and deliver the part with the stuck pin there);
when using the method of screwing two nuts, screw the first one all the way with such great force that it cuts into the cylindrical part of the stud, and use the second nut not a standard one, but a self-locking one (this will allow you to use much greater forces, reducing the risk of unscrewing the nuts);
Heat it several times and let it cool, at the final stage heat it up and unscrew it.

Repeated heating is also indispensable for unscrewing studs mounted on special compounds - thread lockers.

When unscrewing a stuck stud by a welded or screwed nut, it is better to use a tool that is structurally stronger and more tightly covers the perimeter of the working surfaces of the nut, eliminating the licking of the edges:

6-point head instead of 12-point;
Super Lock head instead of the usual one;
ring wrench instead of an open-end wrench;
a crank instead of a ratchet.

How to remove a stud from an exhaust manifold

If a steel pin is stuck in a steel or cast iron manifold, then you can heat it until the metal turns red, using a careful gas torch, a gas torch from a spray can, a blowtorch or other suitable equipment.

How to unscrew the stud from the exhaust manifold to prevent cracks in the cast iron? First of all, you cannot artificially intensively cool a cast iron part. In this case, you need to heat the collector itself, without touching the stud: the collector will warm up and rattle a little in the area of the threaded hole with the soured stud, and the difference in heating of the parts will further weaken the sticking.

What you need to know about stud guns?

It is no secret that any Chinese tool produced “no name” often does not meet the stated technical characteristics.

Its low cost is due not only to production using cheap labor, but also to savings on materials.

This also applies to stud guns, which often cannot withstand even minimal loads when working with fasteners.

Damage to counterfeits most often includes licked notches on the edges of the rollers, deformation of the square head or hexagon head, and even cracks on the body.

Hairpin driver. Purpose, types, characteristics and choice

Unscrewing and screwing threaded connections such as studs without a special tool presents serious difficulties due to the lack of a turnkey head.

To solve this problem, a specialized tool is used - a pin driver.

Purpose of stud guns

Unscrewing studs can be done in various ways using a common tool, for example, the same pliers or using the locknut method.

A broken bolt head turns this fastener into a stud, and if it is impossible to unscrew the remaining part from the part in another way, drilling is performed with inevitable damage to the thread of the hole.

Using a suitable stud driver allows you to not only keep the threads intact, but also safely remove the fastener without damaging it.

In addition, some models of this tool work in both directions, that is, for twisting too.

The principle of operation of the pin driver

The process of unscrewing and screwing the studs is extremely simple.

The pin driver is put on the fastener and clamped using a special mechanism, securely fixed to the pin.

Next, the tool is rotated using an open-end or ring wrench, or using a wrench, which depends on the design of the specific model.

Device and characteristics

The hairpin driver consists of a housing, inside of which there is a clamping mechanism for permanently fixing the tool on the hairpin.

Depending on the device, these can be like collet jaws, the principle of operation of which is similar to the chuck of a drill or screwdriver,

or a wheel (one or several) with notches that are clamped by an eccentric mechanism.

The tool is put on the fastener, fixed by the fastening mechanism, and then rotated.

In other words, the stud driver acts as a removable head for the stud, similar to a bolt.

Various models are made as an independent tool, or can act as equipment.

In the latter case, the body has a hexagon-shaped shank, or a hole for a tetrahedron driver.

Material

The body of the pin driver has a one-piece (often by milling followed by heat treatment) or welded structure, the main elements are made of tool steel, and the clamping elements are usually hardened.

Chrome-molybdenum steel is often used for clamping rollers.

At the same time, a protective zinc, chrome or other coating is applied to the body.

Dimensions and weight of stud guns

Standard stud guns weigh between 100 and 600 grams, and their length averages 60 to 120 mm, depending on the design.

Such models are designed to work with fasteners of dimensions M4 – M19. There are also non-standard options, which are mainly made to order.

Large specimens are designed to work with studs of dimensions up to M180 and larger, weighing up to 15 kg.

As for the size of the connecting square for using a wrench, the most common are 1/2, 3/4 and 1/4 inches.

GOST

There is no separate GOST that defines the technical requirements for pin guns; however, this tool was defined in GOST 16436-70, introduced in 1971 and reissued in 1992.

Loads

Manufacturers often keep a small supply of PDN.

For example, a stud driver for working with 10 mm studs, intended for repairing vehicles, has a maximum permissible load, usually 33 Nm.

Types of stud guns and their prices

Eccentric

It is based on a housing in which there is a hole for fasteners and a hinged eccentric is installed.

The latter is a disk with a corrugated edge surface, which is brought to the hole.

On the opposite side of the disk axis there is a hexagon for a wrench.

To unscrew or screw the fastener, as described earlier, the tool is put on it, then the disk is rotated, as a result of which it is brought to the pin and rests against it.

During rotation, the eccentric mechanism jams the fastening element and transfers the force applied to the tool to it.

This type of stud driver is universal if the body has two holes of different diameters for specific fastener sizes, and “to size” if only one hole is made for the fastener.

An eccentric pin driver can be collapsible or non-dismountable.

At the same time, it is easy to distinguish a domestic instrument from a foreign one - the roller is pressed by turning the body, and not vice versa.

Price – from 1200 rubles.

Hairpin wrench

The tool is reminiscent of the previous version, but has an elongated body in the form of a spark plug wrench, which is why it is called a long drive pin driver.

The principle of operation is similar: when turning the wheel, it clamps the pin, so that it eventually scrolls in the desired direction.

With nut clamp

An outdated design, which, however, is often made at home from improvised materials.

Structurally, this is a body with a handle and a nut located in its lower part, opposite which there is a hole in the body with a thread cut for a bolt.

The latter is used to secure the nut.

During operation, a nut of the required diameter is fixed with a bolt in the body and screwed onto the fastener to be dismantled.

On the reverse side there is a threaded hole for a knob, which, when screwed in, rests against the end part of the stud, tightly wedging it.

Hairpin extractor

A separate type includes a stud extractor, which allows you to remove broken studs and bolts that do not protrude above the mounting hole, that is, they cannot be grabbed by the tool described above.

The operating principle is based on jamming the working part of the tool in a hole pre-drilled in the center of the stud.

Hence another name - internal pin driver.

Fixation in the hole occurs either by hammering (for wedge-shaped and rod extractors) or screwing (for screw spiral extractors).

The cost of the set is around 3 thousand rubles or more.

How to choose a stud gun?

The choice of a pin driver or a whole set of tools is based on the frequency and nature of the work performed.

If we are talking about use in a garage, then the best choice would be an eccentric universal model, which allows you to screw and unscrew a wide range of fasteners.

Moreover, one product will be enough to work with most engines installed in both trucks and passenger vehicles.

For professionals who care not only about speed of work, but also quality, the choice falls on sets of roller pin drivers.

Although the cost of even a single tool of this type exceeds the price of all those described above, in a car repair shop it pays for itself extremely quickly.

What you need to know about stud guns?

It is no secret that any Chinese tool produced “no name” often does not meet the stated technical characteristics.

Its low cost is due not only to production using cheap labor, but also to savings on materials.

This also applies to stud guns, which often cannot withstand even minimal loads when working with fasteners.

Damage to counterfeits most often includes licked notches on the edges of the rollers, deformation of the square head or hexagon head, and even cracks on the body.

How to use a pin driver?

Working with a stud gun does not require any special knowledge, and the whole process is briefly as follows:

The tool is put on a pin.
The eccentric is pressed tightly against the fastener.
The tool is turned with an open-end or spanner wrench using a hexagon, or with a crank inserted into the square hole provided for it.

The direction of rotation depends on whether the fastener needs to be screwed in or out.

NOTE:

Some models of stud drivers are one-sided, that is, they can only be screwed in or out, while others can be screwed in or out.

When starting work, make sure that the eccentric presses the pin tightly.

Manufacturers of stud guns

Among the manufacturers involved in the production of stud guns, the following are popular:

FORCE,
GEDORE
HANS,
Jonnesway,
JTC
KING TONY
WEIDERKRAFT,
Case of Technology,
MASTAK.

Hairpin driver with nut clamp and stop

This tool is quite simple in design, so it is often made at home. The basis of the stud driver is a body with handles, in the lower part of which there is a nut, and in the upper part there is a thread for screwing in a wrench. In the body opposite the nut, a threaded hole is drilled for a bolt or screw, which secures the nut from turning.

This tool works simply. A nut of the required size is installed and fixed into the body with a bolt, the tool is screwed onto the stud with a nut, then a knob is screwed into the body, it rests against the end of the stud and is jammed. Now the body is rotated counterclockwise, and the pin, secured with a nut and a knob, is turned out.

This tool is used correctly only for turning out studs. Despite the simplicity of its design, it requires a large number of operations to work with one pin, so it is not always convenient. Today, stud wrenches of this or a similar design are rarely used; they have been replaced by simpler and more convenient roller and eccentric stud drivers.

Split bushings

They are a fairly little-known device in Russia. Their use is more labor-intensive than the above-mentioned tool. This is the price for better working properties: with their help you can unscrew studs without damaging the threads. Moreover, it is enough that at least three turns of thread are accessible on the stud.

The height of the bushing is divided into two parts. The lower flared part is cut four times and threaded to match the threads on the stud. Here, compliance is required not only in diameter, but also in thread pitch. In the upper part of the bushing, a thread is cut for the mounting bolt and a recess is made to fix the clamp.

The cylindrical clamp in its lower part is a hollow cylinder with an internal protrusion for the above-mentioned sample. In the upper part it has a hexagonal profile, inside which a fastening bolt passes. When using a split bushing, it is first screwed onto the stud with its split part. Then a clamp is put on the bushing from above, with the protrusion along the bushing. By turning the mounting bolt, the clamp is pushed onto the conical lower part with four cuts, compressing it and wedging it onto the threads of the stud. Then the clamp is turned out together with the bushing placed on the stud. For this purpose, a hexagonal profile is used in the upper part of the clamp. After the stud is turned out, the mounting bolt is unscrewed and the stud is released.

Split bushings can also be used for driving studs. There are also split bushings in which the thread for the stud is replaced by knurling. They are used to turn out (or turn in) studs that are threaded on only one side.

How to choose a stud driver

When choosing a stud gun, it is necessary to take into account the nature of the work that will be performed by this tool and its frequency.

For use in a garage, when studs need to be removed only from time to time, the best solution would be a universal eccentric-type stud driver. Such a tool will allow you to work with studs of various sizes (with its help you can unscrew and screw in the studs of almost all engines - from two-stroke scooters to medium-duty trucks, you can also repair other units with studs), it is reliable and easy to use, and has an affordable price. You can also purchase a collet pin driver, but it does not always provide the required degree of fixation and cannot work with large diameter pins.

For professional use in auto repair shops, the best choice would be sets of roller or eccentric type stud guns. Having a tool for a certain size of studs significantly increases the quality and speed of work, and the costs for it pay off in a short time. Although in this case it would not be amiss to have a universal eccentric tool - with its help you can quickly perform simple work.

By choosing the right stud gun, you will provide yourself with a reliable tool that will help solve the most complex vehicle maintenance and repair tasks.

Hairpin driver: simple work with complex fasteners

In the practice of repairing automobile and tractor equipment, there is a need to screw in and unscrew studs - fasteners without turnkey surfaces. For these purposes, a special tool is used - a hairpin driver or a key for hairpins. Read about stud guns, their types, operation and choice in this article.

What is a stud gun?

A stud wrench (stud wrench) is a specialized tool for screwing in and unscrewing threaded rods.

A stud is a fastener in the form of a rod with threads on both ends. The stud is screwed into the product in one part, and a nut is screwed onto the second part.

The design of the stud does not provide special surfaces for the barb (such as the heads of bolts or the faces of nuts) or other tools, which significantly complicates the procedure for screwing it in and out.

As a result, you have to use special tools, which are called stud wrenches or simply stud wrenches.

To properly purchase a stud gun, you need to understand the existing types of this tool, their features and advantages.

Show all products

The main problem of working with studs is to ensure reliable fixation of the cylindrical rod without damaging it and with the force necessary for screwing in or out. Several solutions to this problem have been proposed, and according to the method of clamping the studs, stud drivers are divided into several types:

In this case, all types of tools can have one of two types:

The first type of tool is convenient and easy to use, it is always ready for work, however, as a rule, it has a more complex design and high cost. The second type of tool may have hex keys or a standard size square (usually 1/4, 1/2 and 3/4 inches) for a wrench, ratchet, etc. This tool is more versatile, compact and affordable.

Each of these tools has its own design features and operating principle.

Roller pin driver

One of the most simple in design and reliable tools.

In general, it is a cylindrical body, inside of which there are three cylindrical rollers, between which spacer inserts can be additionally installed.

The inner surface of the housing has a complex profile (triangular with rounded edges and corners, with ovoid elements, etc.), so the rollers, rolling inside the housing, can move closer and further from its central axis.

Eccentric pin driver

This type of tool is also very simple, but it is more versatile than a roller tool.

Structurally, this eccentric pin driver is very simple: its basis is a body with one or two holes for pins, on which there is a hinged eccentric - a metal disk with a grooved edge and the possibility of supply to the holes. Also on the body there is a knob or square for installing a knob, ratchet or other device.

An eccentric pin driver works simply: the tool is put on a pin, the disk is brought to the pin, and the entire tool is turned - when turning, the eccentric rests on the pin, jams it and allows the force necessary for screwing in/out to be transferred to it.

Today, two types of eccentric stud drivers are produced:

It should be noted that there are tools that combine the design features of eccentric and roller pin drivers. This tool has three small eccentrics covering the pin; when the tool is rotated, the eccentrics jam the pin at three points, providing maximum pressure and transmission of high force.

Collet pin driver

This is a universal tool that has a device similar to the collet chuck of a drill and other tools. The basis of this type of pin driver is a body, inside of which there are movable cams. When the body is rotated, the cams converge towards the center, clamping the pin and ensuring that force is transferred to it by hand.

Collet pin drivers are the most versatile, as they allow you to work with pins of various diameters, even non-standard ones. However, the cams do not always provide the necessary degree of fixation of the tool on the stud, so this type of stud driver often cannot cope with the fastener. This is an inexpensive amateur tool that is practically not used in auto repair shops.

Hairpin driver with nut clamp and stop

How to choose a stud driver

When choosing a stud gun, it is necessary to take into account the nature of the work that will be performed by this tool and its frequency.

For use in a garage, when studs need to be removed only from time to time, the best solution would be a universal eccentric-type stud driver.

Such a tool will allow you to work with studs of various sizes (with its help you can unscrew and screw in the studs of almost all engines - from two-stroke scooters to medium-duty trucks, you can also repair other units with studs), it is reliable and easy to use, and has an affordable price.

You can also purchase a collet pin driver, but it does not always provide the required degree of fixation and cannot work with large diameter pins.

For professional use in auto repair shops, the best choice would be sets of roller or eccentric type stud guns.

Having a tool for a certain size of studs significantly increases the quality and speed of work, and the costs for it pay off in a short time.

Although in this case it would not be amiss to have a universal eccentric tool - with its help you can quickly perform simple work.

By choosing the right stud gun, you will provide yourself with a reliable tool that will help solve the most complex vehicle maintenance and repair tasks.

Hairpin driver. A simple solution to a complex problem

In specialized auto repair shops, in production, in construction - wherever you often have to work with studs, a stud driver is used.

Experienced craftsmen who know their business do not need to explain its purpose. And the name speaks for itself.

However, many may not be clear about the design features of the tool, its appearance, how it works and approximately how much it costs.

Design features of the pin driver, principle of operation

The most famous design of this tool consists of a housing in which three rollers are located.

Thanks to the complex inner surface of the body, when rotating, the rollers firmly clamp the stud, ensuring its turning even in difficult cases (fastening automobile manifolds, muffler elements and other places where the thread of the studs “sticks” to the hole of the part into which they are screwed).

On the reverse side of the case, as a rule, there is a square hole for a standard size of ratchets (wrenches), as well as a hexagonal shape of the outer surface for holding with a wrench.

In addition, there are designs whose fundamental structure is similar to the usual three-jaw (collet) chuck. When rotating, the chuck jaws also ensure reliable retention of the pin, which makes it possible to unscrew or tighten it with minimal effort.

This tool is more versatile, since it is supposed to be able to work with studs of different diameters.

Some designs based on the principle of clamping using a rotary eccentric also have a certain versatility (the scope of application is expanded due to the fact that the same tool can be used with different fastener diameters).

Many designs have been invented by those who like to make equipment and auxiliary mechanisms with their own hands - from several nuts compressed together on the free thread of a stud, to relatively complex devices where wedges or eccentrics are used to fix the stud.

If the use will be frequent, then it makes sense to purchase not just one stud driver, but a set for different stud diameters. Rotation can be carried out either manually or using various power tools - screwdrivers, pneumatic impact wrenches or drills.

After the pin is safely unscrewed, the pin driver, turning in the opposite direction, is removed from it.

To be fair, it should be noted that after using this device, the thread of the stud must be restored using a die (the thread turns out to be somewhat dented), especially if the fastener is intended to be reused.

The advantage of using pin drivers

with its help, in the vast majority of cases, it is possible to unscrew a bolt with a broken head without damaging the threads in the part;

the pin itself remains practically undamaged; after running with a die, it is suitable for reuse;

minimum time spent on work;

Made from high-quality steel, the tool is durable and durable;

in hard-to-reach places it is often more convenient to use a pin driver rather than improvised means.

Simply put, the tool makes work easier and faster. It's no secret that a broken, rusty bolt in the absence of special equipment can paralyze all car repair work.

A poorly turned pin can cause the repair time to triple.

Therefore, if the pin suddenly does not want to turn out of a place where its breakage could cause serious problems, it is better to use tools specially designed for this.

Types of stud guns and their prices

Roller pin driver

One of the most effective and at the same time simple.

As a rule, this is a cylindrical body with rollers located inside, sometimes supplemented with spacer inserts.

The inner part of the body has a rather complex shape, through which the rollers move closer and further away relative to the center as they roll.

Before work, the pin driver is put on the fastener and then turned.

On the reverse side for this purpose there is a hole in the form of a square, or a hexagon for an open-end wrench or a head.

As the tool rotates, the rollers roll and move closer to the pin, which leads to its jamming.

Next, the already fixed fastener is unscrewed or screwed in.

The extremely simple principle of operation does not come without a significant drawback - each stud driver of this design is designed to work with studs of a certain size, for example, only M10.

This ensures reliable clamping of the rollers.

For this reason, to work with fasteners of different diameters, the master needs to have a whole set of “multi-caliber” tools.

Professional models are equipped with soft metal rollers, which avoids serious damage to the stud threads.

Cost – from 300 rubles per piece.

For a high-quality set of 4 units you will have to pay from 2.5 thousand rubles.

Collet pin driver

It is considered an amateur tool, as it often does not allow you to cope with firmly seated fasteners.

The reason lies in the principle of operation, which is similar to the collet chuck of a screwdriver or drill.

Structurally, it consists of a body with three cams located inside, which converge towards the central axis when the first one is turned, ensuring clamping of the stud.