10 tips on how to choose a screwdriver: types of screwdrivers, sizes, purpose

A screwdriver is the simplest tool that should always be at hand: at home, in the country, in the garage, because it is difficult to imagine any product, during assembly or installation of which threaded connections are not used. This means that replacement or repair is not possible without a screwdriver. Let us consider in more detail how to choose a screwdriver and what types of screwdrivers will be preferable when performing certain jobs.

1. Design

A screwdriver is a rod with a tip on one end, designed for a certain type of slot, and a handle on the other. Of great importance material and size of the handle. It can be made of plastics, wood or rubber. The shape of the handle must be selected depending on the size of the palm of your hand: the handle that suits you will conveniently lie in your hand.

Handle diameter varies from 10 to 40 mm. The choice depends on the size of the connection, the larger the threaded connection, the larger the handle should be. So you need to make less effort, since the handle directly transfers torque to the part. For small details choose thin screwdrivers with a small handle. Correctly selected size will avoid the destruction of the handle or disruption of the slot. Some screwdrivers have handle hole, which helps to apply even more force when tightening, using an additional wrench. Screwdrivers with interchangeable tips can have a cavity in the handle for storing nozzles.

2. Which tip is preferred?

It's not about the type of tip, but about material of its execution. Indeed, the functionality of a screwdriver depends on the strength of the tip. With prolonged use, especially with improper selection of the type of screwdriver according to the slot, the tip is quickly erased, its edges can crumble and lose their original shape. Working with such a tool is inconvenient and significantly increases the amount of time required for repair or installation. To prevent this from happening, many manufacturers use high-strength materials for the tip, for example, molybdenum steels or chrome vanadium alloys. Many screwdrivers have magnetic tipable to hold small parts, which will be very convenient when working with small screws.

3. What should be the core?

There are rods square, round or hexagonal. Also they have different lengthbut no matter what screwdriver you need, the hardness of its rod according to GOST should be 47-52 HRC. This is an indicator of hardness at which the optimum strength is maintained with internal viscosity, which prevents the destruction of the rod during twisting with great effort. If its strength is less than 47 units, then during operation it will simply bend, and if more than 52 units, then it may burst. Rods, like tips, are made by bona fide manufacturers from chrome vanadium steels. To prevent corrosion formation, the core is coated with a galvanized protective layer.

4. Handle modifications

Not only convenience depends on the shape of the handle of a screwdriver, but also the area of ​​its application. there is the usual, and probably the very first form of screwdriver is a straight line, which has a wide scope due to the variety of sizes. But there are advanced forms of the handle, which greatly simplify the use of a screwdriver.

• T-handle screwdriver. Not all work can be done using a screwdriver with a straight handle, it is universal, but has limitations. If you need to transfer large torque to the part, it is advisable to use a screwdriver with a T-shaped handle. The closer it is to the T-shape, the greater the lever and the greater the moment of force. The handle can optionally be equipped with a hinge that allows you to change the angle between the axis of the screwdriver shaft and the handle axis, thereby adjusting the length of the lever. Such screwdrivers can have interchangeable nozzles, which makes them universal.
• L-shaped screwdriver. Otherwise, they are called L-shaped keys. They have a hexagonal slot or slot in the shape of a six-pointed star - TORX. To be able to work at certain angles, they can additionally be equipped with spherical tips.
• Tipping screwdriver. The handle of such a screwdriver can be “broken” and fixed in the position you need, or even in several. Thus, it can imitate a T- or L-shaped handle, which makes it versatile and very comfortable.

5. Types of screwdrivers

Technological progress does not stand still, and in order to facilitate the work of consumers in every possible way, several improved and quite popular types of screwdrivers.

• Reversible screwdriver. This type of screwdriver is equipped with a ratchet (ratchet mechanism), which allows you to transfer torque from the rod to the tip without intercepting the handle. The rod rotates freely in the handle. With the help of a special switch, in the form of a small lever, it is possible to produce both unscrewing and screwing. The middle position of the switch blocks the ability of the rod to scroll, which makes it possible to use it as an ordinary screwdriver.
• Insert screwdrivers (bits). Insert screwdrivers can have different lengths, the shape of the slot and its size, and also be double-sided. They are considered consumables for screwdrivers or screwdriver-holders into which they are inserted. The screwdriver-bit holder is a handle with a rod, at the end of which there is a special hole in which you can pick up the necessary screwdriver-insert. The bits are fixed in the hole with a collet clamp or with a spring or magnetic holder. Having a screwdriver-bit holder and a set of necessary screwdriver-inserts, you can significantly save, since you do not have to buy a lot of screwdrivers for different slots.
• Flexible shaft screwdriver. This type of screwdriver is very unusual, since part of its shaft is replaced by a flexible shaft or an angular gear transmission, which allows you to change the angle of the shaft and transmit torque from the handle to the tip at almost any angle. This greatly facilitates work in tight spaces or inaccessible places.

6. Functional features of screwdrivers

Some screwdrivers are not quite ordinary, but very useful, additional features.

• Telescopic screwdriver. Using the special structure of the rod, resembling a fishing rod, you can adjust its length, and a special locking mechanism will reliably fix the required length. The tips of such screwdrivers are usually magnetic, which allows you to work in difficult conditions, or get the fallen part in a hard to reach place.
• Impact screwdriver. It happens that a threaded connection can rust, stuck or be coated with paint. The dismantling of such a connection is not easy, because it takes a lot of effort. For such purposes, there are impact screwdrivers, which are made of high strength steels.On the handle of such screwdrivers there is an anvil for impact or a shank - for the possibility of capture with a key, which allows to increase the lever and thereby increase the moment of force. There is also a variety of impact screwdrivers that have a flat shank. When struck with a hammer, it converts the shock force into rotational force, which makes it possible to exert an even greater moment of force on the element to be eliminated.
• Precision screwdriver. This type of screwdriver is used when working with small parts. It has small dimensions and a slot size of up to several millimeters, which allows you to work as accurately and accurately as possible.
• Hour screwdriver.This is the smallest type of screwdriver. Used to repair and replace watch movements. The dimensions of its tip sometimes barely reach one millimeter. On the top of the handle there is a flat platform that allows you to hold the screwdriver in one place with one finger, while the shaft rotates freely. This allows you to unscrew or tighten the smallest details without the need to rearrange the tip and provides high accuracy.
• Indicator screwdriver. An irreplaceable thing when doing work related to electricity. Thanks to a special mechanism built into the handle, the indicator screwdriver allows you to detect the presence of voltage on the element. There is a special contact on the handle, to which you need to attach a finger. If the part is energized, the built-in LED will light up.
• Dielectric screwdriver. A more serious type of screwdriver, designed to work with electricity. The handle is made of a material with high insulating properties, sometimes the screwdriver shaft is also coated with such material, leaving only its tip open. This design allows you to work even on the open terminals of high-voltage equipment, withstanding voltages up to 1000 V.
• Cordless screwdriver. A small battery is built into the handle of such a screwdriver, allowing it to work like a screwdriver. You don’t need to make any effort at all, and the tightening torque will come out a little more than when twisting hands. Such a tool can significantly accelerate repair process or assembly of various products.
• Torque screwdriver. This type of screwdriver is used in high-tech industries, aviation, mechanics, and astronautics. On the handle of such screwdrivers there is a small screen that allows you to measure the tightening force, or a special scale that allows you to set the required moment and make installation of all connections with exactly the same force.

7. Slot shape

Not only the screwdriver handles are diverse, but also the shape of the tip, which is selected depending on the required type of slot. Consider the most common shape of slots:

• Flat head screwdriver SL (Slot). It is a flat, even slot of various lengths, which depends on the necessary force transmitting at a torque. The greater the force required, the wider the slot should be.
• Cruciform PH (Phillips).It has a tip in the form of a cross with different diameters and different thicknesses of faces, depending on size. This form allows you to transfer much more torque than a flat screwdriver due to the fact that its contact area is almost 20 times larger.
• Cruciform PZ (Pozidriv). The tip of such a screwdriver is made in the form of a double cross and has a deeper fit, which makes it possible to better fix it in the slot of the slot and prevent popping up during tightening. Allows you to apply a little more force than when working with a screwdriver.
• Hexagon Hex. The tip of such a screwdriver resembles a hex wrench and is used to work with the corresponding slots. Due to the larger area of ​​the fit, it allows you to transfer 10 times more force with torque than a flat screwdriver.
• Screwdriver TORX. Tip Torx imitates the shape of a six-pointed star. This unusual shape prevents the abrasion of faces, both on the screwdriver and in the slot of the threaded connection. With it, it is possible to exert more force on the part than with a regular hexagonal screwdriver. There are also tips Torx with a small pin inside.

8. Non-standard slots

In addition to such tips, some manufacturers have released screwdrivers specifically designed to work with special threaded fasteners. Thus, manufacturers secured themselves against unauthorized actions by ordinary users and secured warranty service for their products. Fasteners with non-standard slots can be found in household appliances, digital technology or engines of modern cars.

• Square screwdriver. It is very rare, according to the name it has a square tip and a very narrow scope. It is a type of hex screwdriver HEX.
• Shamrock screwdriver. A custom screwdriver that has the Tri-Wing designation. Connections with such a slot are almost impossible to disassemble on their own, which ensures the safety of manufacturers' copyrights.
• Asymmetric Cross. A very rare type of screwdriver, which is almost never found in everyday life and is used mainly in the aerospace industry. It is designated as Torq. Its main advantage is that it allows you to perform such a strong tightening torque like no other screwdriver.
• Spanner screwdriver. This screwdriver has a slot in the form of two pins. This type of connection is used in the manufacture of household appliances and elevator facilities. This unusual type of tip allows you to avoid dismantling the housings of household appliances or elevator mechanisms by unscrupulous users.

9. Slot size

We got acquainted with the possible forms of the slots, but in order for the screwdriver to serve for a long time and not be erased, it is necessary to correctly determine the required tip size. To determine the size of the slots, there are special standards in which each of them is assigned numbers. Flat-head screwdrivers have a width of 2 to 18 mm. Phillips screwdrivers RN and PZ are numbered from 0 to 4 and vary depending on the diameter of the external thread of the fastener. For instance:

• screwdriver No. 0 is designed for an external thread diameter of up to 2 mm
• No. 1 - from 2.1 to 3 mm
• No. 2 - from 3.1 to 5 mm
• No. 3 - from 5.1 to 7 mm
• No. 4 - more than 7.1 mm

Depending on the number of the screwdriver, the diameter and length of its shaft depends:

• Screwdriver No. 0 has a shaft diameter of 4 mm with a length of less than 80 mm
• No. 1 - rod diameter 5 mm, length from 80 to 100 mm
• No. 2 - rod diameter 6 mm, length from 100 to 120 mm
• No. 3 - rod diameter 8 mm, length from 120 to 150 mm
• No. 4 - rod diameter 10 mm, length from 150 to 200 mm

10. What to look for when choosing a screwdriver?

In specialized stores, the choice of screwdrivers is so great that anyone would be confused. Sometimes sales consultants may come to your aid, but, unfortunately, they do not always recommend really high-quality products, so you should rely only on yourself. The only thing you can do directly in the store is to carefully examine the product, how it will cope with its main task, you can only evaluate after the purchase, so be careful.

Pay attention to the handle first, hold the screwdriver in your hand. it should lie comfortably in your palm and not slip. The hilt itself, whatever material it may be, must be made carefully. If it is rubber, it should not have pores or excess material at the junction. Then pay attention to the rod, some manufacturers apply a marking indicating which material it is made of. The presence of such markings may imply factory quality. The tip, as the most critical part of the screwdriver, must be very durable.Look at its color, if it is darker than the core, this indicates additional hardening, which is a clear advantage. Even such little things can help you decide and choose the best product that will last you for many years.