What types of jigsaw files exist and how to choose the best option for a particular case should be known to every craftsman who has this tool in his household.

There are many factors that influence the choice of cutting blade: the material that will be sawed, its thickness and density, the required cut quality, etc. In order not to make a mistake when purchasing, you should take into account the technical characteristics of the files, as well as the advantages and disadvantages of a particular model.

Material for making cutting blades

The first thing you need to pay attention to when choosing a file is the material from which it is made.

Each cutting blade from well-known manufacturers has its own marking. Knowing how to decipher it, you can easily determine whether the file is suitable for you for the upcoming work.

The marking indicating the material used to make the canvas is as follows:

Table on the use of files.

1. HCS. These files are classified as woodworking tools. They are made of high-carbon steel, which has ductility and elasticity. They can cut wood, chipboard, plywood and plastic. When choosing such a fabric, you should pay attention not to its hardness, but to its flexibility.
2. H.S.S. Hardened steel products that can be used at high speeds. Used for processing durable materials, including metals of varying densities. Despite all its rigidity, hardened steel is a rather brittle substance that must be used very carefully.
3. BIM. Bimetallic blades, which are made from a mixture of high-carbon and hardened steel, due to which they have all the advantages of the first two types. Depending on the shape and size of the teeth, they can be used for both wood and metal work.
4. HIM. They are made from high-strength alloys, due to which they are characterized by high strength and rigidity. Mainly used for cutting ceramic tiles.

The color of the file can also indicate the material of manufacture and purpose of the file:

• white (BIM) – for cutting wood and metal;
• gray (HCS or BIM) – for processing wood and wood-based materials;
• blue (BIM or HSS) – for cutting metal;
• black (HIM) – for performing special tasks (sawing ceramic tiles, durable steel, etc.).

Marking of jigsaw files

Files intended for working with wood are marked with the letters HCS.

On the tail of any jigsaw cutting blade there is a marking consisting of letters and numbers. The first is the letter “T” or “U”, which indicates the type of attachment of the blade to the tool: T-shaped or U-shaped. It is followed by numbers indicating the length of the file:

• 1 – short blade (up to 7.5 cm);
• 2 – standard cutting element (7.5-9.0 cm);
• 3 – extended file (9-15 cm);
• 7 – long file (more than 15 cm).

The longer the product, the thicker the workpiece it can cut.

After the numbers there are again letters that indicate the size of the teeth:

• A – the smallest teeth (perfect for cutting laminate);
• B – larger teeth (used for processing wood, fiberboard, chipboard and plywood);
• C and D are the largest teeth used for rough cutting.

Some manufacturers use two letters at the end instead of one (for example, T101BR). The second letter means:

• O – for figure cutting;
• R – s reverse tooth(improves cut quality);
• F – bimetallic products (considered the most durable and reliable);
• X – universal blade (it can cut both wood and metal);
• P – thick files (used for corner cutting).

For example, the marking T118AF means that the selected model has a T-shaped mount and fine teeth, its length is up to 7.5 cm, and the material of manufacture is bimetal.

Types of saw blade shanks.

When choosing a cutting blade for a jigsaw, you need to know what material it will work with. This tool capable of cutting not only wood and wood-based materials (chipboard, fiberboard, plywood, etc.), but also plastic, slate, brick, metal and even tiles. Moreover, for each material being processed there is a type of saw with which the jigsaw will work with the best efficiency. There are also universal cutting blades, which are equally suitable for wood and metal, for example.

Wood files. Depending on their purpose, such products are divided into two groups:

• for quick cutting;
• for a clean cut.

If you are faced with the task of sawing a large number of wood, spending a minimum of time, then the best option would be a cutting blade with large teeth.

How more teeth, the faster the cut takes place. However, as the speed of work increases, the cleanliness of the cut decreases, so here you need to choose between speed and quality.

If speed of work comes first, then the best option would be a blade marked T101D. With its help, you can quickly cut wood blanks up to 7.5 cm thick; for thicker material, you can purchase the T244D or T344D model.

For a clean cut good option is the file T101B. It is often used for professional purposes when assembling furniture and other work that requires high-quality cutting. This product can also cut thick workpieces, but you will spend twice as much time on this as when using, for example, the T244D model.

Canvas on laminate. When laying laminate flooring, it is important that the cut does not have burrs. This can be achieved using the T101BR file, which is equipped with a reverse tooth. However, if you don’t have this model at hand, and you need to cut the laminate with something, you can get by with the regular T101B blade. Only in this case, before starting work, it is recommended to cover the area of ​​the intended cut with ordinary tape, which will protect the processed material from chips, burrs and other defects.

Metal files. They have fine teeth and a blue tail. If you will be working with metal 3 mm thick, buy a T118A file. It is also suitable for cutting plastic. For thicker material, it is recommended to use a T123X cutting blade, and for aluminum - T227D.

Files for tiles. They are marked T150RIFF or T130RIFF. Instead of teeth, their cutting part is carbide coating. You need to know that using a jigsaw to cut tiles is recommended only in extreme cases, since the work will be slow and dusty. For lack of specialized tool To cut tiles, it is better to use a regular glass cutter.

Blade shape

For various tasks a certain tooth shape is suitable, which differs not only in the type of sharpening, but also in the setting method:

1. Milled set teeth. This blade is perfect for cutting wood. Divorce is carried out by analogy with ordinary hand hacksaw. This allows you to slightly widen the cut, thereby preventing overheating and jamming of the tool in the thickness of the wood.
2. Milled teeth with wave setting. In this case, not a single, but a group setting is performed (for example, 4-6 teeth). Similar files are used for cutting metals.
3. Ground teeth without setting. The best option for finishing cutting. This canvas allows you to achieve High Quality cut in wood, laminate and plastic.
4. Set teeth with grinding. This product is used for quick cutting when there are no special requirements for the quality of the cut.

Manufacturers of jigsaw files

To choose the right file for an electric jigsaw, you need to pay attention not only to the technical characteristics and labeling of the product, but also to the manufacturer. On the market construction equipment cutting blades are presented in a wide range of European, domestic and Chinese models.

Chinese files are not of the best quality; they quickly wear down and overheat. Their only advantage is low cost. However, it will be cheaper and easier to choose one high-quality canvas for 300-400 rubles than to purchase a set of 20-30 Chinese products for 150-200 rubles. But, if you still need to saw, but there is no file at hand, you can sharpen the old one.

The most popular and reliable jigsaw files are products from Makita, Bosch and Praktika.

A few useful techniques for working with a jigsaw:

What is a jigsaw? - historical reference

The popular Makita jigsaw had a predecessor, which was completely undeservedly forgotten. The manual jigsaw was replaced by laser cutting, jigsaw, and milling.
With a hand jigsaw you can cut wood, plywood, plastic, ceramics, sheet metal. Previously, in schools, during labor lessons, children practiced cutting out homemade products with a jigsaw - frames, shelves, dolls and other homemade products. There was no time for gadgets...

Jigsaw design

A jigsaw is a U-shaped arc (1), at the ends of which there are clamping screws (4). A handle (3) is attached to the lower end of the jigsaw. Between the ends of the jigsaw arc, a file (2) is secured using clamping screws, which is installed with some tension (until it rings).
A jigsaw with a wooden arc has a third screw - a tension screw, which serves to tension the file between the ends of the arcs, since a jigsaw with a wooden arc does not have sufficient elasticity to tension the file to working condition.

Files for hand jigsaws (a, b, c) are made of high-quality carbon steel. but despite this, cutting out with a jigsaw is enough painstaking work, requiring patience and attention. I hurried a little and trinket! You need to insert a new file.

What can you do with a jigsaw?

The modern jigsaw has replaced the manual jigsaw from many areas of activity, but if you need an accurate, curved cut, a regular, manual jigsaw cannot be replaced.
Craftsmen still use a jigsaw in jewelry production
for cutting complex figures from gold and silver. Using a jigsaw to cut out various shapes from plywood and wood for handicrafts is an excellent hobby; your hands are busy and your nerves are like ropes.

Standard blades for hand-held jigsaws have a length of 130 mm, with a variety of modern manufacturers You can find options with a length of 150 and 160 mm. Types of files are classified according to two main parameters: their size and tooth configuration.

In general terms, blades for manual jigsaws are similar to, but have one important difference: pinless saw blades with flat ends are always chosen, which can be secured in tool clamps and easily threaded into thin holes when creating small patterns.

The dimensions of files for a manual jigsaw are similar to those for machine tools: from #2/0 to #12. But practice shows that the most optimal options for manual sawing there are numbers from #3 to #9.

Which files are better?

The quality of cutting directly depends on the characteristics of the blade. Therefore, it is better to always choose products from trusted brands. Their products are made of high-quality carbon steel; the blades have clearly formed teeth with a positive sharpening angle; The blades are hardened to achieve maximum hardness and increase service life. The overpayment in this case turns out to be a justified investment in ease of use, high quality of project execution and long service life of the blade.

Let's understand the basic concepts

The marking of saw blades for a manual jigsaw contains basic information that allows you to choose the blade that is optimal for a specific type of wood and the project as a whole. To decipher this marking, it is important to become familiar with the key concepts.

TPI – a value indicating the number of teeth per inch of blade. For a manual jigsaw, it is appropriate to choose blades with a high TPI coefficient. They cut wood more slowly, but allow better control over the line of cut.

Reverse tooth – a blade with a reverse-directed tooth, which cuts the material during the return movement of the saw, thereby preventing the formation of chips on the wrong side of the sawn product. They are especially relevant when using plywood blanks.

Tooth set – created to prevent the saw from jamming in the workpiece, which in turn ensures trouble-free cutting (especially sharp turning and curved lines) and minimizes the formation of chips. The width of the cut when using such files increases slightly, which should be taken into account when making the project.

Classification of files

Based on the characteristics of the teeth configuration, blades for manual jigsaws are classified into the following types:

1. Standard (Standard Tooth) - classic files whose teeth have the same size, direction and distance from each other.
2. Files with a missing tooth (Skip-tooth Blades) – the absence of teeth ensures effective removal of chips from the surface of the workpiece and increases sawing speed. Unlike classic options, they heat up less and jam less often.
3. Double tooth files (Double-tooth Blades) – these blades cut a little slower, but leave a perfectly smooth cut line. They also effectively remove chips and overheat less.
4. Reverse files (Reverse Skip-tooth) - blades, part of the teeth of which are directed upward. They cut the wood during the return motion of the jigsaw, which reduces the number of chips by back side blanks.

Dimensions table

The table presented contains basic information regarding the size and marking of modern files for manual jigsaws. By referring to it, you will know how to choose the correct blade number for sawing wood of a specific thickness.

Despite the varied palette of options, the gold standard for sawing with a hand jigsaw are the blades number #3 , #5 And #7 .

At first, it can be difficult for beginners to control the file, which constantly moves to the side. Without gaining the necessary experience, it is advisable to use canvases With great value TPI: They cut slower but allow for better control of the cutting line.

Working with saws with reverse teeth is not the best The best decision for a beginner. In order to master this blade you need some experience. Otherwise, the workpiece will jump up and the sawing itself will be very slow.

What to choose for thin plywood?

When working with thin material use canvases with maximum number teeth per inch. Thin blades with a high TPI value cut less aggressively, put little stress on the fragile edges of the workpiece, and do not pull the jigsaw to the side. These characteristics make them optimal for cutting small details and patterns from thin plywood.

A hand jigsaw is a convenient tool that allows you to cut not only wood, but also other materials. To obtain a high-quality cut without wasting unnecessary time, you need to install a file that will ideally cope with the task. Therefore, you need to know the characteristics of the product and be able to choose the right jigsaw files.

Shank type

The shape of the part of the file inserted into the jigsaw - the shank - determines the way it is clamped in the tool.

Files with a tail resembling the letter T are ubiquitous. They are suitable for most modern models jigsaws for wood, such as those developed by BOSCH, a trendsetter in this field. In jargon they are called "European type".

American models (DeWalt, Black&Decker) use saws whose tail end ends in a semicircular cutout resembling the letter U. Such shanks fit all clamps with a block or screw. In the jargon - “American type”.

There are still special Makita shanks and T-shaped “Bosh” shanks, but with two stops. They are suitable only for old models of jigsaws from these companies and, rather, are rarities.

Tooth shape

The width and cleanliness of the cut, as well as the suitability of the saw for cutting specific materials, depend on the method of sharpening and setting the teeth of a jigsaw on wood. There are 4 categories.

The first category includes milled files with a regular set. The classic divorce is the alternate bending of the teeth in different sides. A regular saw or hacksaw has such a problem. It produces a wide kerf and high cutting speed, but does not provide cleanliness. top scores are obtained by quickly cutting any type of wood, plastic and even metal.

The second category is milled with a “wave” type pattern. The teeth are not set one by one, but in groups of several pieces. The amount of spread is different for each tooth in the group, so the cutting edge looks like a wave. This file provides good cutting quality and is used for different materials when it is necessary to obtain an even and smooth cut without chips.

Next come files with ground teeth and a classic alternating set. They are characterized by high cutting speed and a wide kerf, the cleanliness of which is better than that of the milled version. Their purpose is fast but high-quality cutting of wood and wood-based materials (chipboard, fiberboard).

Finally comes the category of jigsaw files for wood without cutting with conical grinding of the teeth. The absence of a mark gives a clean and thin cut, but is not suitable for fast and rough cutting. Used for finishing wood and polymers.

Tooth pitch

The pitch is the distance between the two closest teeth of the saw blade. It is measured in millimeters and denoted by the letter t. Marking t3 means a tooth pitch of 3 mm. But often when marking this parameter, it is not the pitch (distance) itself that is used, but the inverse value - a number showing the number of teeth per inch of blade length. The generally accepted designation is TPI. The higher the TPI, the more frequently the teeth are spaced and, therefore, the smaller the pitch.

According to this parameter, jigsaw files for wood are divided by type of work:

• for rough cross cuts, TPI = 4–7 (t = 3.5–6.5) is suitable;
• ordinary carpentry – TPI = 7–9 (t = 2.5–3.5);
• high quality cuts – TPI = 9–13 (t = 2).

When choosing a suitable step, you need to pay attention to the thickness of the material being processed. The cutting process should involve 5–7 teeth. If the thickness of the material is small and the tooth pitch is large, the blade will vibrate and tear the cutting edge.

Canvas dimensions

Not only the size and shape of the cutting edge determine the capabilities jigsaw files. The geometric characteristics of the canvas itself also affect the speed and quality of work. Plus, its dimensions must be selected based on the type and dimensions of the material being processed.

Length

The lengths of jigsaw blades are in the range of 40–250 mm. When choosing a specific length of a jigsaw file, you need to take into account the thickness of the material in the work. It is clear that for sawing thick wooden blanks You need a long saw blade for a wood jigsaw. But if you cut thin sheet materials with a long blade, then due to the possible bending of the metal, it is difficult to obtain an even cut.

Note! When working with long blades, you should understand that the working depth of the cut is affected by the power of the jigsaw.

Width

You need to select the width of the saw blade based on the type of work to be done. For simple sawing, where a straight and even edge is required, take wide files. A narrow blade may move during operation, and a straight cutting line will not work.

But when figure sawing With varying degrees of complexity, you need to choose narrow jigsaw blades. It is easier to direct them to the side, drawing curved lines.

Thickness

For sawing thin sheet materials, the thickness of the file does not matter much. But when working with thick workpieces, this size affects the quality of the sawn surface. Thin blades will deviate from the perpendicular line during operation, and the cut will be uneven. The thicker the blade, the more even the cut it provides. But there is one caveat - too thick a blade is not suitable for all models of jigsaws. Jigsaws equipped with quick-release devices may not be suitable for thick blades.

What do the markings on files mean?

Even knowing all the intricacies of choosing a suitable jigsaw file and having determined the required parameter values ​​for yourself, you can get confused among the many products offered. Don’t go to the store with a ruler and calipers, measuring the dimensions of each blade and the pitch of the teeth!

On files from well-known manufacturers it is necessary to apply different markings, giving approximate information about the parameters of this product. Of course, if you want to know the exact values, you can measure them with a ruler. But it is better to do this not with every canvas, but only with one - pre-selected by marking.

There is no mandatory labeling standard. Most manufacturers of jigsaw files adhere to the rules adopted by BOSCH. It is rare, but you can find markings that differ from these rules.

According to BOSCH standards, alphanumeric markings are applied to the shank of the jigsaw file. The first letter of the marking indicates the type of shank: T-shaped or U-shaped.

The number following the letter refers to the length of the canvas. But this is not the length itself, but the number of the corresponding length range.

1 – short files with a length of up to 75 mm;

2 – average length: 75–90 mm;

3 – long: 90–150 mm;

4 – very long, more than 150 mm.

The next two numbers encrypt the purpose of the file (according to the manufacturers). The same information is usually present in other places on the saw blade in a form that is more understandable to the consumer.

The first letter following the numbers indicates the tooth size:

• A – small;
• B – average;
• C and D – big.

The second letter (if there is one) gives Additional information about files that are somewhat different from ordinary ones.

F – especially durable material, bimetal.

O - small width, for figured cutting.

P – large thickness.

R – reverse direction of teeth.

X – teeth of variable size.

Important information about the purpose is duplicated by the markings twice: by the color of the shank and the words on the canvas itself.

For wood - grey colour; the words Wood (plain wood) and HardWood (hard wood and laminate).

For metal – blue color; the words Metal (metal), Alu (aluminum), Inox (stainless steel). Universal tool for wood and metal - white.

For polymeric materials – red color; the words Acrylic and Fiber&Plaster (fiberglass).

For other materials – black; for example Soft-material (soft materials - rubber, foam).

For ceramics – Ceramics.

Elsewhere on the canvas there may be verbal information about the method of application and special properties (usually in smaller letters than about the material of use):

• basic – standard type of canvas;
• speed – for fast cutting;
• flexible – with a “wave” type connection;
• clean - without streaks, clean cut;
• progressor – variable tooth size;
• special – for highly specialized applications (ceramics, durable plastic, etc.)

A letter marking of the type of metal from which it is made is applied to the neck of the file (between the shank and the blade itself):

• HM – hard alloy;
• CV – chrome vanadium alloy;
• HSS – high-speed steel;
• HCS – high carbon steel;
• VM or ViM is a particularly strong alloy.

Thus, by studying the markings on a jigsaw file, you can obtain comprehensive information about it.

Types of files according to purpose

The word jigsaw still evokes associations with wood. And although modern jigsaws are widely used for sawing plastics and metals, the main material for work is still wood and plywood. You also have to think most often about which blades to choose for a jigsaw on wood.

On wood

For general work on wood and its derivatives (plywood, chipboard, MDF), standard saw blades with a gray shank for simple or hard wood are chosen. The dimensions of the blade, the spread and the size of the teeth are selected individually. But sometimes it is necessary to perform work that differs from ordinary sawing.

If speed is important, even at the expense of the quality of the cut, then you need to choose long files with large teeth and big step. Divorce is also desirable more.

If you need to get an even and smooth cut without chips, then take blades with a small mark or without it at all. Teeth – medium or fine. Materials that have a finishing side (laminate, chipboard) have to be cut upside down. If you want to see the cut from the front side, then you need to choose files with the teeth in the opposite direction (the last letter of the marking is R).

For artistic cutting there should be a narrow blade no wider than 4 mm, small teeth and short length. Compliance with these conditions will allow figure cutting to be carried out at small turning radii.

For metal

An electric jigsaw is still not the best suitable tool for cutting metal. But if necessary, he can handle it if you choose the right file. The teeth of such files are very small and wavy; the blades are made of especially strong alloys, but they also quickly become dull. It is advisable to select files marked specifically for the type of metal you will be working with.

For polymer materials

The file markings contain designations specifically for working with such materials. Ordinary plastic and PVC products can also be sawed with wood blades. In this case, the teeth must be chosen larger and with a larger spread. A small tooth will not only cut, but also melt the material. For plexiglass, it is better to choose a metal fabric with a wavy pattern.

Manufacturers

BOSCH is considered the leader in the production of jigsaw files. This is perhaps the only company that provides its tools with a full range of saw blades. HITACHI and MAKITA are also popular, but they sometimes use other manufacturers to produce instruments. From domestic files with good quality You can note the products "Ermak".

In general, the range of products is quite wide, but in order not to make a mistake, it is recommended to give preference to proven brands.

Let's try to understand the labeling of such a common consumable as a jigsaw file.

The purpose is determined by the color of the shank on the side of the alphanumeric designations. If the shank

• gray - the file is intended for sawing wood:
• white - for wood and metal
• blue - only for metal work
• red - for sawing plastics
• black - other materials

Now let's go over the alphanumeric symbols mentioned above. Let's go in order.

First comes the letter T or U. It indicates the type of saw attachment. The more common T-shaped mount, but there is also a U-shaped one - see diagram

The letters M (Makita) and F (Fein) may also appear

The following numbers indicate the working length. They can be 1,2,3,7

1. short (length up to 75 millimeters)
2. medium (length from 75 to 90 millimeters)
3. long (length from 90 to 150 millimeters)
4. very long (length exceeds 150 millimeters)

The second and third numbers show the purpose of the file itself.

F - bimetallic files. They are of the highest quality: they cut cleaner and faster, last longer
O - narrow files for curved cuts
P - thicker files, due to which they move less from side to side and the cut is perpendicular to the surface.
R - regressive blades, that is, with a reverse tooth
X - universal blade (for any materials)

Then comes the steel grade

HCS(high carbon steel) - high carbon steel, its hardness is 45-48 HRC. This steel is optimal for work on soft materials, (wood and its derivatives - MDF, chipboard, fiberboard, as well as plastics);

CV(chrom vanadium) - Chrome is vanadium steel, its hardness should be 50-52 HRC. It is more wear-resistant compared to the previous one. Used for the same materials;

H.S.S.(high speed steel) - high-speed steel, also known as high-speed steel, hardness of at least 61-65 HRC, used for processing hard materials(aluminum and other non-ferrous metals and even mild steel). Compared to HCS, HSS files are thinner, but have significantly greater hardness;

BIM(bi-metal) is a combination of HSS and HCS steels in one sheet. Files of this kind are expensive and are usually used for professional use. They take both wood and metals well;

H.M.(hard material) - the hardest grade of steel, tungsten carbide hard alloy, hardness 79 HRC. Such blades are used for special types of work - cutting fiberglass, tiles and aerated concrete.

This classification is quite arbitrary and is not followed by all manufacturers. Therefore, it is worth discussing each file separately.

Files used for woodworking

T101B- this is a fairly short fine-toothed file (length 74 mm). Designed for working on soft wood, plywood up to 30 mm thick. The fine tooth allows for a clean cut.

The same thing, but with the teeth in the opposite direction. Excellent for cutting materials where chips on the front surface are undesirable (for example, table tops). When working, additional force is required to press the jigsaw onto the material, since the working stroke throws the tool up.

T101P- has a larger tooth compared to T101B (4.5 mm). Allows you to cut the same materials, but their thickness can reach 45 mm.

An even longer file (91 mm), the maximum thickness reaches 65 mm.

A narrow thin file with a fine tooth (1.4 mm) is used for clean curved cuts of wood and its derivatives with a thickness of 1.5 - 15 mm.

Short fine-toothed bimetal file. Designed for sawing laminated materials up to 15 mm thick. - the same, the nose has a larger tooth (2.7 mm), the thickness of the materials reaches 30 mm.

The same, but with a reverse tooth.

This is a file with a fairly thick blade and large teeth (4 mm). The teeth are set apart. Due to its thickness, the file is more stable in one plane and does not move to the side. Disadvantages - it is a rough cut with a lot of chips.

The same thing, but with a bimetallic blade, it is more expensive, cuts longer and has a better length of 74 mm.

This file is twice as long as the above-mentioned one - it is 126 mm.

T345XF is another long bimetal file (106 mm). Its tooth is quite large. Designed for cutting wood with nails, plastic, metals (including aluminum).

Specialized metal files

T118A- a short, fine-toothed file for metal sheets no more than 13 mm thick.

T318A- this is a longer file, great for cutting metal pipes with a diameter of no more than 65 mm.

T118G- the file has the smallest teeth (0.7mm) and is designed for cutting the most thin sheets metal (0.5-1.5 mm)

Universal files

T234X, T123X are universal saws for cutting various types wood, plastic and metal.

Special files

Thin saw blade of stainless steel(up to 2 mm)

Longer file for steel 2-5 mm thick

Fiberglass file. Thickness limit 65 mm

Drywall saw and cement particle boards up to 50 mm thick

Longer blade (106 mm), which makes it possible to cut materials up to 85 mm thick

T101A- file for plexiglass up to 20 mm thick

T113A- file for leather, rubber, cardboard up to 50 mm thick. Has no teeth, has cutting edge, similar to a knife.

Longer saw blade for similar materials up to 100 mm thick. Has a wavy blade

T130Riff,T150Riff - saw blades designed for cutting ceramic tiles. They are equipped with diamond coating. T130 is intended for rough cuts, and T150 is for finishing cuts.

T308B, T308BF - file, for cutting materials laminated on both sides. Thanks to two rows of teeth, the number of chips is minimized. This is a fairly thin file, so it shakes quite a lot from side to side.