What are the bits for a screwdriver
Types of bits and their purpose
Screwdriver bits differ in the shape of the working part, on which their purpose depends.
All types of products can be purchased as a set, which is much cheaper than buying them separately.
But before that you need to make sure the quality of the bits.
To make the right choice, you need to know the types, sizes, bits, their main differences and the material from which they are made.
How to choose bits for a screwdriver
To make it easy and convenient to work with a screwdriver, you just need to choose the right bits.
At the same time, it is desirable to choose high quality products, even if their cost may be a little overpriced.
Before buying, you should study the recommendations for choosing bits from specialists.
You need to clearly understand what material you will work with, since bits for screwing self-tapping screws into wood and installing metal structures must be designed for the appropriate loads.
It affects the strength of the product and its service life.
For products not intended for intensive loads, steel R-7. R-12 is used.
This material is characterized by increased resistance when working with metal.
Such products have a protective coating of chromium and vanadium.
Products with a titanium-nitrium coating of a golden hue are considered more reliable.
When milling to give the work area the desired shape, the top surface is removed.
When forging, the material is given the desired shape after heating the metal, while it is not disturbed.
Therefore, forged products are more reliable.
Hardness of materials
Soft attachments wear out faster, but they are more resistant to damage, so they can be used for hard attachments.
Hard tips are more fragile.
It is recommended to purchase bits with a hardness of 58-60 HRC.
Some models are equipped with a magnet, but their use is limited.
Its presence is not always an indicator of quality.
For example, these attachments are not suitable for an impact screwdriver.
How to evaluate the quality of bits for a screwdriver
So that in the process of work there are no difficulties in the choice of consumables, you should approach responsibly.
Therefore, it is recommended to know in advance how to evaluate the quality of the bits before purchasing.
Bits for nuts and bolts
These bits have a non-standard shape.
Their peculiarity lies in the fact that they do not have a convex working part, but with a hole, while there are a large number of standard sizes.
It must be remembered that to tighten nuts and bolts with a large diameter of the head, you need to use a screwdriver with high power.
bits for straight spline
They are most like a simple screwdriver.
At the end they have a slot, which can have different widths.
Understanding Basic Screw Bit Types
This allows you to choose the optimal size to achieve your goals.
Width is measured in millimeters.
This parameter is indicated on the working part.
On the construction market, you can purchase products for a straight slot with a width of 0 to 7 cm.
They also differ in length.
Some products are equipped with special stops that allow you to adjust the screw-in depth.
Most often this type is used to work with plasterboard structures and furniture.
The classic cruciform nozzle has 4 ribs.
Allows you to work with metal and wood products.
Cross-shaped bits with a cross-shaped element in the form of a flat tip can be considered universal, since they allow you to work with countersunk screws, fasteners with a medium pitch and with Pozi-type fasteners.
The sizes of self-tapping screws with which you can work vary in the range from 2.5 to 4 mm, while the presence of rust or damage on them does not matter.
You can also use the cross-shaped bits to screw in and out screws and bolts that are at different angles.
Hex bits are used in furniture assembly.
Designed to work with internal hex fasteners.
There are models with a hexagonal hole, thanks to which the fixture does not slide off the screw.
The size of the nozzle can vary from 1.5 to 6 mm.
There are products with increased length.
They are used extremely rarely, although they are characterized by practicality and convenience.
The length of the nozzle can vary from 50 to 100 mm.
The slot resembles a hex star, while there is a choice of different diameters.
This parameter is measured in millimeters.
Star-shaped models are most often used when working with automotive equipment or where it is necessary to apply high forces to tighten fasteners.
The advantages of such a product are that you do not need to make great efforts to create torque, and the risk of the device slipping is minimized due to the fact that the entire load is distributed over six points.
This reduces wear and tear.
There are models with a hole inside.
Most often they are used in assembly plants.
The tightening process with its help is characterized by increased reliability and does not require special efforts.
non-standard bit shapes (special)
They can also have non-standard insert shapes, for example, a square working half, four blades, etc.
Such products are highly specialized, therefore they are practically not popular.
Spring and magnetic
Bits with a spring clip or a magnetic tip are designed for working on ceilings or other hard-to-reach places.
Retainers are designed to hold the bits in the adapter.
The magnetic tip allows you to securely fix the bit in the screw grooves.
It is also able to prevent the screwdriver nozzle from slipping during operation and allows you to screw the self-tapping screw deeper than a simple nozzle.
The spring attachment is a special.
It allows you to work with fasteners that are at different angles and in hard-to-reach places.
Most often it is a slot and a base, which are connected by a flexible spring for fastening: you need to fix the slot of such a nozzle manually, insert it into the notches on the self-tapping screws, while the spring can be bent at any angle, even more than 90 °.
Classification by material and coating
Particular attention should be paid to the material from which the bit is made, its coating. Most of the work is done by the surface of the nozzle, and low-quality materials will lead to rapid tool wear.
Quality bits are available in various alloys:
- molybdenum with vanadium;
- molybdenum with chromium;
- will win;
- vanadium with chromium;
- high speed steel.
The latter material is cheaper and subject to rapid wear and tear, so it is not considered when comparing performance.
The soldering of the bit is made of spraying:
- tungsten carbide;
The outer coating is always applied, it provides protection against corrosion, increases wear resistance and improves the strength of the material from which the element is made. Titanium soldering appears in golden hues.
Triangular tips are marked with the letters TW (Tri wing) and the size range from 0 to 5. The head of such a tool looks like a trihedral with rays. Models are used with Phillips screws. This type of screws is usually used in foreign household appliances to protect against unauthorized opening of the equipment. To fix the drywall, nozzles with a limiter have been created, which does not allow screwing the screw deeper than the stop.
Square bits are of a highly specialized nature. Designated with the letter R, the spline consists of four faces and is available in four sizes. Square bits are used in the assembly of large furniture.
Long bits available up to 70 mm.
Fork bits are flat-slotted with a central slot. They are designated by the letters GR and come in four sizes. Type. standard, extended, length up to 100 mm. The four- and three-bladed bits are labeled TW. These are professional attachments used in the aerospace and aviation industries.
Non-standard types are included in conventional bit sets, but are not used in home repairs, so it is advisable to give preference to sets containing standard and cross-shaped nozzles for a nut, screw, screw and other fasteners.
Angle and long screwdriver nozzles are designed for work with fasteners in hard-to-reach places. They are flexible and solid, allow you to screw in and out the screws. Made of durable materials, non-magnetic.
Impact or torsion nozzles are designed to relieve the effect of the torque that occurs when the screw is screwed into the soft layers of the working surface. These attachments are used only with an impact screwdriver and do not require an increased load on the device. Bit marking. color.
Such a tip resembles a six-rayed star in shape. These bits are used in the repair of cars and foreign household appliances.
The tips are available in sizes from T8 to T40, indicated in millimeters. Sizes below the T8 value are produced by manufacturers for highly specialized screwdrivers used in microelectronic technology. Star-shaped nozzles also have a second marking. TX. The number in the marking indicates the distance between the rays of the star.
The six-beam insert creates a secure grip on the bit to the bolt without excessive force. This shape minimizes the risk of screwdriver slipping and bit wear.
Torx hole campaign bits come in two flavors: hollow and solid. This point should be considered when buying.
Which is better in operation?
The question of bit exploitation always remains relevant.
- German kits from Belzer and DeWALT represent above average quality products. In the first minutes of work, wear of the fasteners, small breaks of the bit, breakthroughs on low-quality elements appear, but after a few minutes the wear stops. These changes are happening with all the bits of different firms. German bits are the most impact-resistant.
- Bits of all sizes and types are presented in large sets of HITACHI 754000, they are suitable for craftsmen of large repair and construction companies. The quality of the bits is average, but it is compensated by the number of nozzles. With a careful attitude, the service life will be unlimited.
- Kraftool introduces chrome vanadium alloy tips. The set consists of 42 items, one of which is a case. ¼ ”adapter included.
- Makita (a German company). a set of chrome vanadium steel, represented by common types of splines. The bits are designed to work with a screwdriver, but a manual screwdriver is also included. In addition, there is a magnetic holder. All elements are of high quality.
- The American Milwaukee set provides craftsmen with a working surface, each of which is designed with Shock Zone technology, which protects the bit from kinking during operation. Excellent elasticity and impact resistance of the material ensures a long service life.
- The Metabo set is color coded. Each type of spline is color coded to make it easier to store and retrieve a particular bit. The set contains 9 elongated bases of 75 mm and 2 nozzles.
Material. chrome vanadium alloy.
- Ryobi is a Japanese company that focuses on duplicating popular bits in different lengths. The magnetic holder is made in a non-standard format, looks like a bushing on a hexagonal shank, because of this, loose magnetic fixation of the fastener and the bit is possible. In general, the set has sufficient strength and quality materials.
- The Bosch company has established itself as a company producing quality products that enjoy the prestige of craftsmen. Most used bits are gold titanium coated, but tungsten-molybdenum, chrome-vanadium and chrome-molybdenum bits are more durable. Titanium is replaced with nickel, diamond, and tungsten carbide to protect against corrosion and reduce wear. The titanium coating increases the price of the product, but it will also last longer. For short-term and rare works, you can choose ordinary hardware.
- If you need to replenish the kit with individual pieces, it is worth taking a look at the Whirl Power tools, marked with a green marking. Possesses excellent hardness and magnetism, fasteners hold for a long time. The bit adheres tightly to the chuck, does not fall out. The standard bit WP2 in most cases is used to fix screws, but for self-tapping screws, WP1 is intended. The length of the bits is different, the size range is 25, 50 and 150 mm. The tips have notches that are responsible for the wear resistance of the material. Bits of this brand have proven themselves in the market, are used by construction firms and private craftsmen.
These bits are found in all bit sets, as they are used in almost any job. Bits for a straight slot appeared first, today such nozzles are used when working with screws and screws, the head of which has a straight section.
Equipment for a flat slot is marked S (slot), after which there is a number indicating the slot width, the size range is from 3 to 9 mm. All nibs have a standard thickness of 0.5-1.6 mm and are not labeled. The tail indicates the material from which the nozzle was made. All elements have increased erosion protection and hardness.
Titanium slotted bits are incredibly durable. Gold plating is swept away with the letters TIN, indicating that the tip is made of titanium nitride. These tips are wider than standard. up to 6.5 mm, and slightly thinner. up to 1.2 mm.
Slotted nozzles are often reversible, in combination with a cruciform tip. This is due to the versatility and frequent demand for the product. The thickness of a flat bit is usually not indicated, since it has an internationally accepted standard from 0.5 to 1.6 mm.
Some rigs are available in an extended version. Due to the length, the possibility of tight contact between the screw and the nozzle is achieved, which improves the quality and accuracy of work.
How to choose?
If you buy a product by the piece, it is important to select models with:
- the presence of a protective coating;
- high impact resistance.
When purchasing a set, you should pay attention to slightly different parameters.
- The material from which the bits are made. The better it is, the fewer problems will occur in the work.
- The way the item is processed. There are two types of processing. Milling is the least durable option due to the removal of the surface layer of the material. Forging is a homogeneous structure. Heat treatment of bits allows them to be used in various modes with increased load.
- Profiling. Designed to ease handling of tough fasteners.
Such bits should not be used on anti-corrosion, chrome-plated, brass screws, due to the possibility of damage to the working surface of the element.
- Micro-roughness. Bits with rough edges, coated with titanium nitrides, are used to secure fasteners with a special coating.
- Hardness. The standard value for most attachments is around 58-60 HRC. Bits are divided into soft and hard. Hard bits are fragile, but they are more durable. They are used for low torque fasteners. Soft, on the other hand, are designed for hard mounts.
- Design. Metal tips should not be used in work where shavings from the same material are present. This will complicate the fixing process and lead to wear on the workpiece.
Many firms produce bits with their own markings, but in a standard form. Philips puts the letters PH on the cross heads and produces them in 4 sizes: PH0, PH1, PH2 and PH3. The diameter depends on the size of the screw head. The most commonly used PH2 is used in home work. PH3 is used by craftsmen in car repairs, furniture assembly. The bits range in length from 25 to 150 mm. Flexible extensions are designed for fastening work in hard-to-reach places.
This shape allows you to fix the screw at an inclined angle.
Pozidrive cruciform bits are double-shaped. Such a nozzle ensures reliable operation with torsional moments; strong adhesion occurs even when the screw head is turned at a small angle in relation to it. The size range of bits is marked with the letters PZ and numbers from 0 to 4. The PZ0 tooling is designed for small screws and screws with a diameter of 1.5 to 2.5 mm. The largest head PZ4 fixes the anchor bolts.
Hex head fastening material is secured with hexagonal bits. Such screws are used in the assembly of heavy furniture, repair of large equipment. A special feature of hex fasteners is the slight deformation of the bolt head. This should be taken into account when twisting the clamps.
Bits are divided into sizes from 6 to 13 mm. The most common bit in everyday life is 8 mm. It is convenient for them to tighten screws and carry out roofing work. Some bits are specially magnetized with metal hardware. Because of this, magnetic bits are one and a half times more expensive than conventional ones, but at the same time they greatly facilitate and speed up the work with fasteners.
What affects the durability of the bits
To choose quality tips, it is not enough just to remember the name of the recommended manufacturer. Even one company has products of different quality, which will affect the usability and service life of the tooling. Here are two key factors affecting bit longevity to consider when buying.
Construction or what are torsion bits
In addition to the material, the design of the tooling affects the service life of the tooling. It is of two types: rigid and flexible. Outwardly, the bits look almost the same. the difference can only be in the color insert on the leg of the latter. But now they are producing products without it.
A hard bit is simply a piece of metal in a certain shape. It transfers torque from the gearbox to the fasteners. When a self-tapping screw stops abruptly in a solid material, a strong blow occurs, which leads to knocking down the edges in the head and nozzle or breakage of the bit.
The torsion bit is equipped with a flexible insert. a shaft capable of twisting and unwinding along the axis. Such bits are well suited for impact screwdrivers when you need to screw a long self-tapping screw into a dense material or, on the contrary, unscrew old fasteners. The bit transmits well the tangential impact from the power tool, and instead of slipping out of the grooves, it acts on the slots in the head, providing rotation. Impact bats last much longer than normal ones.
The best models of bits for a screwdriver
Having considered two key factors affecting tool life, we turn to specific manufacturers and models, which will help you choose the right attachments for different activities. The following is a rating of bits for a screwdriver based on tests, in descending order. Hence, the best ones are at the top. At the same time, their price is different, so those that are lower may sometimes turn out to be more expensive than those that are higher.
Milwaukee Shockwave Impact Duty
American company, founded in 1924, and distinguished by innovative ideas in the field of power tools and accessories to it. He has over 300 personal patents and is actively applying new technologies. Her top line of bits, the Milwaukee Shockwave Impact Duty, achieved the highest rating in tests with 6,088 screws per attachment. Here are the features and technological solutions of this line.
Bits from this series became TOP winners both in the experiments of Russian and foreign specialists. All models in the series are torsion bar and are designed for impact tools. Shockwave denotes a special treatment of the tip, giving precise positioning on the fastener and reducing resonance oscillation. The bit material is resistant to heat during intensive use.
This model is available in structural steel with a forged tip. The body has a red torsion bar. Sold individually or in sets. There are all types of attachments:
- TX with a diameter of 1.0-5.0 mm and a length of 25-90 mm;
- SL with flat slot the choice is not large. the thickness of the tip is from 0.6 to 1.2 mm and the width is 4.5-5.5 mm;
- The reinforced PZ has a diameter of 1 to 3 and a length of 25 to 90 mm;
- PH without amplification with the same dimensions;
- Hex with an edge size from 2.5 to 12 mm and a length of 25 mm.
Since the splines of the nozzle are subjected to the highest stress, the material from which they are made is one of the important factors affecting the durability.
The most common materials for making screwdriver bits are:
- Steel R7-R12. the cheapest, suitable only for screwing self-tapping screws into soft materials (wood, plastic).
- Tungsten-molybdenum is a stronger and more versatile material.
- Chromium-vanadium is the most common tool alloy that can withstand high loads. Can be used for frequent metalworking.
- Chromium-Molybdenum is the hardest alloy for long tip life.
The service life of the bit material is also affected by whether it has been hardened. Heat treatment contributes to the hardening of the tool end, which more effectively resists deformation from loading.
In addition to the material of the bit itself, its coverage is important. It is designed to either protect steel from corrosion or increase its strength. Low-cost options include a chromium vanadium coating that allows the tip to resist corrosion despite exposure to moisture. But with intensive use of the tool, it quickly erases.
Chrome Vanadium Plated Bits.
reliable is titanium nitride or pure titanium coating, which can be recognized by its characteristic golden color. The coating effectively protects against rust and increases the strength of the tooling.
Titanium nitroite coated bits.
The tungsten coating is also equal in terms of the degree of impact.
The leader in terms of the stability of the outer layer is the diamond coating. It significantly increases the working life of the bit, eliminates the slipping of the splines from the fastener grooves and increases the speed of monotonous processes.
Best screwdriver bits based on tests
Screwdriver bits ensure that the fastener is held firmly and screwed into the material to the desired level. The most common problem with this attachment is the loss of the shape of the splines (licking), after which the attachment becomes useless.
We analyzed the results of numerous tests that were published both on the Russian Internet and on foreign resources, and made a rating of nozzles and their manufacturers. Thanks to this, you will find out which bits for screwdrivers are the best, which will help you choose the right accessories that can last for many years and not waste your money.
Another American brand that has long gained popularity in Europe. The DeWALT FlexTorq series is a recent innovation, marketed as the most geometrically correct bits. During the bit tests, it was found that one bit is enough to screw up to 2592 self-tapping screws.
Bits are made from forged blued steel with subsequent machining. Due to this, the shape of the tip especially closely follows the cutouts on the heads of the fasteners, which reduces backlash and increases the contact area. The torsion core is capable of unscrewing along the axis by 15 degrees, which protects against a sudden stop of the self-tapping screw.
The series includes conventional and reinforced cruciform nozzles in sizes from 0 to 3 and lengths of 25 or 57 mm. A large selection of sprockets in sizes from 10 to 40 and lengths of 25 and 57 mm. Among the flat bits, there are only two options with a blade width of 6 or 8 mm.