- 1. Design
- 2. Which tip is preferable?
- 3. What should be the rod?
- 4. Modifications of
- handles 5. Types of
- screwdrivers 6. Functional features of
- screwdrivers 7.
- slot shape 8. Custom
- slotts 9.
- slot size 10. What should I look for when choosing a screwdriver?
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 that does not use threaded connections when assembling or installing it. 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 works.
A screwdriver is a rod with a tip at one end, designed for a certain type of slot, and a handle at the other. Of great importance is the material and the size of the handle. It can be made of plastic, wood or rubber. The shape of the handle must be selected depending on the size of the palm: the handle that suits you will be comfortable in your hand.
The diameter of the handle 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, because the handle directly transmits torque to the part. For small parts choose thin screwdrivers with a small handle. The correct size will avoid the destruction of the handle or the disruption of the slot. Some screwdrivers have an hole in the handle, which helps to apply even more force when tightening, using an additional key. Screwdrivers with interchangeable tips can have a cavity in the handle for storing nozzles.
2. Which tip is preferable?
This is not about the type of the tip, but about the material of its execution .After all, the functionality of the screwdriver depends on the strength of the tip. With prolonged use, especially with the wrong selection of the type of screwdriver in accordance with the slot, the tip is quickly erased, its faces may crumble and lose their original shape. Working with such a tool brings inconvenience 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 tip , capable of holding small parts, which will be very convenient when working with small self-tapping screws.
3. What should be the rod?
The rods are square, round or hexagon .They also have with different lengths of , but whatever screwdriver you need, hardness of its core according to GOST should be 47-52 HRC. This is an indicator of hardness, which maintains optimum strength with internal viscosity, which prevents the rod from breaking when tightened with great force. 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, as tips, bona fide manufacturers make from chrome-vanadium steels. To prevent the formation of corrosion, the rod is covered with a galvanized protective layer.
4. Modifications of
handles Not only convenience, but also the area of its application depends on the shape of the screwdriver handle. There is the familiar , and probably the very first form of the screwdriver is the straight , which has a wide range of applications due to the variety of sizes. But there are improved forms of the handle, which greatly simplify the use of a screwdriver.
- Screwdriver with T-handle .Not all work can be done using a straight screwdriver, it is universal, but has limitations. If you need to transfer a large torque to the part, it is advisable to use a screwdriver with a T-shaped handle. The more it is close to the T-form, the greater the lever and the greater the moment of force will be. The handle can be additionally equipped with a hinge, which allows you to change the angle between the axis of the screwdriver rod and the axis of the handle, thereby adjusting the length of the lever. Such screw-drivers can have replaceable nozzles that does them universal.
- L-shaped screwdriver. Else they are called L-shaped keys. They have a hexagonal slot or a slot in the shape of a six-pointed star - TORX.To be able to work at certain angles can be additionally equipped with spherical tips.
- Fracture 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 convenient.
5. Types of
screwdrivers. Technical progress does not stand still, and in order to facilitate the work of consumers in every way, several improved and quite popular types of screwdrivers were invented.
- 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 scrolls freely in the handle. With the help of a special switch, in the form of a small lever, it is possible to make both unscrewing and screwing. The average position of the switch blocks the ability of the rod to scroll, which makes it possible to use it as a normal screwdriver.
- Screwdriver inserts( bits). Screwdrivers-inserts can have different length, the shape of the slot and its size, as well as be two-sided. They are considered consumable for screwdrivers or screwdrivers-holders, which are inserted. The bit-screwdriver 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 bit is fastened in the hole with a collet clamp or with a spring or magnetic holder. Having a screwdriver-bit holder and a set of necessary screwdrivers-inserts, you can significantly save, because you do not have to buy a lot of screwdrivers for different slots.
- Screwdriver with flexible shaft. This type of screwdriver is very unusual, since part of its rod is replaced by a flexible shaft or an angle gear that allows you to change the angle of the rod and transfer torque from the handle to the tip at almost any angle. This greatly facilitates work in cramped conditions or hard-to-reach places.
6. Functional features of
screwdrivers. Some screwdrivers have some extra features that are not very common, but very useful, .
- Telescopic screwdriver. With a special rod-like structure, it is possible to 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 to get a fallen part in a hard-to-reach place.
- Impact Driver .It happens that the threaded connection can rust, get stuck or be painted. Dismantling such a connection is not easy to carry out, because it takes a lot of effort. For such purposes, there are impact drivers, which are made of high-strength steels. On the handle of such screwdrivers there is an anvil for impact or a shank - for being able to be captured with a key, which allows increasing the lever and thereby increasing the moment of force. There is another kind of impact screwdrivers that have a flat shank. When struck with a hammer, it converts the impact force into a rotational force, which makes it possible to apply even greater moment of force on the element being eliminated.
- Precise screwdriver .This type of screwdriver is used when working with small parts. It has a small size and slot size up to several millimeters, which allows you to carry out the work as accurately and accurately as possible.
- hour screwdriver. This is the smallest variety of screwdrivers. Used to repair and replace watch movements. The size of its tip sometimes barely reaches 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 rod rotates freely. This allows for the unscrewing or screwing up of the smallest details without the need to rearrange the tip and ensures high accuracy.
- Indicator Screwdriver. An indispensable thing when working on electricity. Thanks to a special mechanism built into the handle, the indicator screwdriver allows to detect the presence of voltage on the element. On the handle there is a special contact to which you need to put 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 rod is covered with such material, leaving only its tip open. This design allows you to work even on the open terminals of high-voltage equipment, maintaining the voltage up to 1000 V.
- Battery-powered screwdriver .In the handle of such a screwdriver is built a small battery that allows it to work as a screwdriver. You generally do not need to put any effort, and the torque will come out a little more than when tightening your hands. Such a tool can significantly speed up the process of repair or assembly of various products.
- Torque screwdriver .This type of screwdriver is used in high-tech industries, aviation, mechanics, 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 torque and install all connections with exactly the same force.
7. Shape of the slot
Not only the screwdriver handles are diverse, but also the shape of the tip, which is selected depending on the required slot type. Consider the most common shaped splines:
- Flat screwdriver SL( Slot ) .It is a flat, smooth slot of various lengths, which depends on the required force, which is transmitted at torque. The more effort you need to apply, the wider the slot should be.
- Cross-shaped PH( Phillips). It has a cross-shaped tip with different diameter and different thickness of edges, depending on the size. This form allows you to transfer a much larger torque than a flat screwdriver due to the fact that its fit area is almost 20 times larger.
- Cross-shaped 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 hole and prevent it from jumping out during the tightening. Allows you to make a little more effort than when working with a PH screwdriver.
- Hexagon HEX. The tip of such a screwdriver resembles a hex key and is used to work with the corresponding slots. Due to the larger contact area, it allows you to transfer 10 times more force at torque than a flat screwdriver.
- Screwdriver TORX. The tip of the TORX simulates the shape of a six-pointed star. This unusual shape prevents the erasing of faces, both on the screwdriver and in the slot of the threaded connection. With the help of it, it is possible to exert more force on the part than with a conventional hexagonal screwdriver. There are also TORX tips with a small pin inside.
8. Non-standard splines
In addition to these tips, some manufacturers have released screwdrivers specifically designed to work with special threaded fasteners. Thus, manufacturers have protected themselves from unauthorized actions by ordinary users and provided themselves with warranty service for their products. Fasteners with non-standard vents can be found in household appliances, digital technology or engines of modern cars.
- Square screwdriver .It is very rare, according to the name has a square tip and a very narrow scope. It is a type of hexagonal screwdriver.
- Trefoil Screwdriver. Custom screwdriver, which has the designation Tri-Wing. It is almost impossible to disassemble connections with such a slot on your own, which ensures the safety of manufacturers' copyrights.
- Cross asymmetric .A very rare type of screwdriver, which practically does not occur in everyday life and is used mainly in the aerospace industry. It is denoted as Torq. Its main advantage is that it allows you to perform such a strong tightening torque, like no other screwdriver.
- Screwdriver Spanner. This screwdriver has a slot in the form of two pins. This type of compound is used in the production of household appliances and elevator industry. 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 reviewed the possible shapes of the splines, 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 are 2 to 18 mm wide. Cross-head screwdrivers PH and PZ are numbered from 0 to 4 and differ depending on the diameter of the external thread of the fastener. For example:
- screwdriver №0 is designed for external thread diameter up to 2 mm
- №1 - from 2.1 to 3 mm
- №2 - from 3.1 to 5 mm
- №3 - from 5.1 to 7 mm
- №4 - more than 7.1 mm
Вdepending on the number of the screwdriver depends on the diameter and length of its core:
- The screwdriver No. 0 has a core diameter of 4 mm with a length of less than 80 mm.
- No. 1 has a core diameter of 5 mm, a length of 80 to 100 mm.
- No. 2 has a core diameter of 6 mm, a length of 100 to 120 mm.8 mm, length from 120 to 150 mm
- No. 4 - rod diameter 10 mm, length from 150 to 200 mm
10. What should I look for when choosing a screwdriver?
In specialized stores, the choice of screwdrivers is so great that anyone would be confused. Sometimes sales assistants can come to your rescue, but, unfortunately, they do not always recommend a really high-quality product, so you should rely only on yourself. The only thing you can do directly in the store is to inspect the goods carefully, how it will cope with its main task, you will be able to evaluate only after the purchase, so be careful.
Pay attention first to the handle, hold the screwdriver in your hand.it should lie comfortably in your palm and not slip. The handle itself, of whatever material it is, 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 put a label indicating what material it is made of. The presence of such a marking 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 rod, this indicates additional hardening, which is a clear advantage. Even these little things can help you decide and choose the best product that will serve you for many years.