Classification and types of bits for a screwdriver
In our time, the construction and installation work has been greatly simplified. This, in particular, is facilitated by a huge number of fasteners, which are very easy to use with an electric screwdriver or drill / driver. Nails are currently being used less and less. Both amateurs and professional craftsmen increasingly prefer screws and screws, as these fasteners provide the most durable fastening. However, for each fastener, its own nozzles are used, without which your screwdriver turns into a useless toy. To make it easier to navigate in the variety of nozzles, we present to your attention the classification of bits for a screwdriver. You will find out what types and sizes of bits the industry produces and for which fasteners this or that bit is used.
Content:
Slotted Bits
The very first screwdriver was invented under a straight slot, it was invented in the XVI century. It was widespread during the Soviet period. Today, there are also types of bits for a screwdriver made under a straight slot, but they are used less often. Such nozzles are marked with the letter S. This marking is placed on one of the faces of the bits. The Latin letter S is an abbreviation for the English word slot, meaning "slot" or "slot." There is also an alternative notation - slotted. When translated into Russian, this word means "slotted". Always next to the letter is a number indicating the width of the sting. In some cases, its thickness is additionally indicated.
The ratio of the width and thickness of the most common bits under a straight slot:
| Width mm | 2,0 | 2,5 | 3,0 | 3,5 | 4,0 | 4,5 | 5,0 | 5,5 | 6,0; 6,5; 7,0 | 8,0 | 9,0 |
| Thickness mm | 0,3 - 0,4 | 0,4 | 0,5 | 0,5 - 0,6 | 0,6 - 0,8 | 0,6 | 0,8 | 0,8 - 1,0 | 1,0 - 1,2 | 1,2 - 1,6 | 1,4 - 1,6 |
Next, we consider some types of bits under a straight slot.
Classic Slotted Bit
Width and thickness are the two main dimensions of a straight slot. In most cases, only the first parameter is specified. It ranges from 3.0 to 9.0 mm. The second parameter is often not indicated, but its value can be from 0.5 to 1.6 mm. The peculiarity of this marking is due to the fact that the width and thickness have a normative ratio. The surface of the flat slot bits is protected against erosion and is characterized by increased hardness.
Direct Slotted and TIN Coated Bits
These bits have a golden color, as the surface of the nozzles is coated with titanium nitride as a result of the CVD chemical process. Due to this, the devices have a solid surface. Such nozzles may differ from each other only in width. This value is between 4.5 and 6.5 mm. Even in the labeling of devices, their thickness can be indicated. This value ranges from 0.6 to 1.2 mm.
Elongated bit under straight slot
Due to the elongated part of the device, it is possible to more accurately carry out the necessary work. When using, the tip of this nozzle is firmly placed in the head of a screw or screw. Using this bit, it is convenient to perform small installation processes. A distinctive feature of these devices is the length of the nozzles, which ranges from 50 mm to 100 mm.
Cross bits (Phillips)
The first cross-shaped bat appeared in the first half of the 20th century. This was facilitated by the fact that when using fasteners and screwdrivers under a straight slot in the automotive industry, when assembling parts, they often expressed screws and screws from the caps, which led to damage to the lacquered coating of the vehicle.Also, fasteners often broke the thread due to the fact that torque limiters had not yet been invented, which subsequently began to be used in mechanical screwdrivers and screwdrivers.
All of these reasons contributed to the fact that in 1933, John Thompson invented a screw with a cross-shaped slot. After 3 years, the patent for this invention was acquired by Henry Phillips. This engineer finalized the production technology and in 1937 proposed to Eugene Clark, who was a major manufacturer of metal products, to hold a competition, who would be quicker to tighten the screws. Naturally, Henry Phillips won the match. After this, a new type of nozzle attracted the attention of automakers from the United States, but World War II soon began. Therefore, a cross-shaped slot appeared in Europe, along with the supply of American military equipment.
The first cruciform nozzle was called "phillips" in honor of Henry Philips. Bits of this kind are marked with the letters PH. After them follows a number that is tightly connected with the diameter of the external thread of the fastener. This standard is used for all types of bits with a cross-shaped sting.
Standard ratios of the number of the cross-shaped bits of type PH and the external thread of the fastener:
| Bit number | 0 | 1 | 2 | 3 | 4 |
| Thread diameter mm | less than 2.0 | 2,1 - 3,0 | 3,1 - 5,0 | 5,1 - 7,0 | more than 7.1 |
Classic Phillips Bat PH
These nozzles vary in size, which range from 0 to 4. Most often used crosspiece number 2, as it allows you to work with metal and wood material. Less commonly used are large nozzles numbered 3 and 4. Most often they are used during car repairs and bulky items.
Cross bit with PH slot and TIN coating
Titanium nitride is used to cover the nozzle. This is evidenced by the golden color of the bits. The nozzle is able to withstand heavy loads. The slot can be made in one of three sizes: PH 1, 2 or 3.
Elongated Phillips Bit PH
The elongated nozzle with a PH slot of a cross-shaped shape can be used to tighten fasteners in hard-to-reach places. Such devices are especially effective during unscrewing fasteners. Most often, you can find nozzles with a length of 50, 70, 90, 110, 125, 150 mm. Available in three sizes PH 1, 2, 3.
Cross bits (Pozidriv)
Later, specifically for furniture and construction, the Philips Screw Company developed a new type of cross-shaped slot. It is called Pozidriv (Pozidriv). This type of slot was patented in 1966. Bits for a given slot are marked with the letters PZ. They are designed to work with wood or other similar materials that have a heterogeneous structure. At the same time, bits like PH are more suitable for working with metal.
A distinctive feature of the PZ system, in comparison with PH, is that the edges of the working surfaces are parallel to each other and are made with the same thickness along their entire length, and the slot itself is much deeper. This design feature prevents the ejection of bits when twisting the fasteners. Due to this, a more tight contact is formed between the screw head and the bat, which reduces the wear of the elements. In this case, it is not necessary to apply large axial forces when the sting is pressed on the slot.
It must be remembered that when choosing bits for twisting fasteners under the PZ slot, you need to use a PZ bit. In the case of using a nozzle type PH, for twisting products under the slot PZ, the surfaces will not come in contact with each other, which will reduce the service life of the nozzle.
Classic PZ notched bit
Additional notches are a hallmark of PZ bits when compared with PH nozzles. The great strength of the devices allows them to withstand huge loads. The sizes of this type of bits for a screwdriver can be PZ 1, PZ 2, PZ 3.
PZ slotted bit with notches and TIN coating
The protective coating of this nozzle is made on the basis of titanium nitride. It greatly enhances the durability of the bits. This is also facilitated by the hardened steel used for its manufacture.All of this combined allowed us to create a nozzle with optimal hardness and endurance. There are three sizes of fixtures: PZ 1, PZ 2 and PZ 3.
Extra long cross head PZ
This nozzle is available in three sizes: PZ 1, PZ 2, PZ 3, the length can be - 50, 70, 90, 110, 125 and 150 mm.
Hex Slots
Another, less popular, but often used is the hexagonal slot. This notch shape first appeared in 1910 and is called the Hex socket. This phrase denotes an internal hexagon. For the first time they began to use it in the factory floors of Allen Manufacturing Company. The letter H is used to mark these bits. The Hex system has a large torque that can be applied to the head of the fastener when it is twisted. However, there is no likelihood of damage to the nozzle and disruption of the slot.
The distance between the sides of the hexagonal tip is the main characteristic that distinguishes between such bits. If you take a nozzle of 4 mm, then it is perfect for twisting furniture confirm. A so-called safe type of slot is also available. He received the name Hex-Pin, which means a protected hexagon. This slot is equipped in the center with a special pin. Its presence helps to prevent unauthorized disassembly of the connection.
Classic Hex Bit
These bits allow you to very conveniently work with the corresponding screws and screws, as they have a large area of contact with fasteners. They have long been used in the United States, but in Russia their implementation has occurred relatively recently. The sizes of these nozzles can vary in the range from 1.5 to 10 mm.
Hexagonal Bit with Hole Inside
A reliable bit of this kind is easy to use. During its application, a person does not need to exert great physical strength. Due to the presence of the hole, the device does not slip. The nozzle size is from 1.5 to 6 mm.
Extended Hex Bit
This nozzle is marked with the Hex- mark. It is rarely seen in work. Despite this, she has proven herself well, as she is distinguished by practicality and convenience. For the manufacture of this bits used high quality steel. In this regard, it has good strength. Its sizes range from 3 to 8 mm, and the length of such nozzles varies from 50 - 100 mm.
Asterisk Bits (Torx)
We use nozzles in the form of an asterisk in the engineering field and in the manufacture of household appliances for twisting fasteners with the appropriate shape of the head. They are called Torx and are indicated by the letters TX or T. Next to the letter is a number that indicates the size of the nozzle. It corresponds to the distance between the rays of a hexagonal sprocket.
For the first time, Torx began to be used in 1967 by Textron, in America. Today, different types of bits are used for a screwdriver of this type. So, there is an anti-vandal version equipped with an internal hole. For its designation, the letters TR are used, which are decrypted by Torx Tamper Resistant. Five beams called Torx Brigadier Pentahedron are also used.
Classic Asterisk Bit (Torx)
In European countries and the USA, the Torx nozzle is the most popular of all existing slot forms. This is due to its high performance. This bit is distinguished by the presence of six faces, with the help of which there is contact with a screw or screw.
The design feature of the nozzle improves adhesion to the surface of the fastener. Thanks to this, you do not need to exert much effort to create torque. Also, the likelihood of slipping off the device is reduced, since the load is distributed immediately to 6 faces.In turn, this reduces their wear. Therefore, the operational period of the bits is significantly increased. Asterisk nozzles of various sizes are available. The most common are models from T8 to T40. In this case, there are bits and a smaller size.
Asterisk bit Torx Plus
Torx Plus differs in that its asterisk has less sharp rays, which are also shorter. These types of bits for a screwdriver require the master to be more accurate during work. Highly hard steel is used for their manufacture. The sizes of these nozzles are T10 -T40.
Asterisk bit with TIN coating
Due to the presence of a coating based on titanium nitride, the nozzle has increased wear resistance. Its surface is rough and adheres well to steel. Also, the nozzle is characterized by increased durability, because it is made of solid material. The nozzle is sold with sizes from T10 to T40.
Asterisk bit with a hole inside
This bit is often used in assembly plants. When tightening the fastener, the bit fits tightly into the fastener. As a result, the reliability of the twisting process is increased, for the implementation of which, no special efforts are required. Sizes of bits are from T10 to T40.
Extended bit "Asterisk"
This nozzle is convenient to use when performing certain types of work. Its dimensions are the same: from T10 to T40, the length can be from 50 mm to 100 mm.
Square Slot Bits (Robertson)
These nozzles belong to specialized types of bits. In most cases, they are not used in ordinary construction or in repair processes. Slot Robertson is one of the rarities and has a square section. Its full name is Robertson square. Nozzles of this shape are indicated by the letter R.
Classic four facet bat
Most often they are used during the assembly of furniture. Such nozzles are available in 4 sizes: from No. 0 to No. 3.
Four-faceted extended bit
This nozzle is not used so often. It is available in three sizes: No. 1,2 and 3 and can be long from 50 to 70 mm.
Vandal proof slot (Spanner head)
This slot is also called Snake-eye (snake eye). In addition, it is also called a head designed for a fork key. For marking bits with such a slot, the letters SP are used.
Classic bat "Fork"
In the manufacture of these nozzles, high-quality steel is used. Thanks to her bits are characterized by high strength and long durability. This nozzle resembles a flat slotted bat, which has a slot in the middle. The bat is issued 4 sizes, Gr. 4, 6, 8, 10.
Extended bit "Fork"
It is made in 4 sizes and can have a length of 50 mm to 100 mm.
Tri-Wing Slots - Three Blades
When marking these nozzles, the letters TW are used. A distinctive feature of these bits is the presence of 3 blades on the sting. They are used in the assembly of household appliances and electronics. They are also used in the aerospace industry. These bits first appeared in 1958 and were invented by the Philips Screw Company. The size is indicated by the letters Gr and can have indicators from Gr.1 to Gr.6.
Bits - Four-blade Torq-Set
This bit is an analogue of Tri-Wing, but differs with it in the number of so-called wings. It has 4 blades. This nozzle is also used very rarely. For its designation, the letters Gr are used, the size varies from 4 to 10.
Some rare slots and bits
Polydrive
Spline
One way
