Saws: specifications, types

The type determines, first of all, the general principle of the saw device; in some cases this is directly related to the purpose (see below).

— Standard. The most common variety, the one that is also called the "wide saw": a classic tool that has a fairly wide blade, tapering towards the end, and a characteristic (usually D-shaped) handle. The vast majority of standard models are designed for woodworking, this is a fairly convenient and versatile option; however, there are also models for other purposes. The only material for which classic saws are unsuitable is metal.

— Luchkova. Bow saws use a blade in the form of a narrow metal plate, as well as a special frame in which it is fixed with two ends during operation. The frame stretches the canvas to the sides, providing the tension necessary for work and minimizing the likelihood of deformation; in other words, such saws do not spring during operation. Another bottom of the key advantages of bow saws lies in the collapsible design. Due to this, when dulling, you do not need to buy a new saw, just buy a new blade. In addition, this design is very convenient for multi-purpose saws (see "Intended use"); and even many models, originally specialized for one purpose, allow the installation of "non-native" canvases. In general, the bow design is considered optimal for saws for metal, and most of these saws are original for this purpose. Among th...e disadvantages of this type, we can mention the poor suitability for working with thick or long materials: when the blade is immersed to a great depth, the frame will most likely rest against the edge of the workpiece, not letting the tool go further. However, this moment can be partly offset by the use of rotary canvases (see below).

— Pasovochnaya. Sawing saws are designed to make cuts with high precision, including using a joiner's miter box (in some models it is even included in the kit, see below). The most noticeable feature of such a tool is a wide rectangular blade — this is done in order to ensure maximum rigidity and reduce deformation during operation. The teeth in the pass models are small (at least 9 per inch), often without a divorce — this improves accuracy and reduces wear on the miter box. One of the most popular applications for such saws is the preparation of tenon joints.

— Mini saw. Saws are small in size, similar in layout and dimensions to conventional knives (and held, usually, in the same way). They may have different purposes. Due to its size, the productivity of such a tool is not high, but it can be extremely convenient for small-scale work, when a full-size saw is not required. And in a limited space where there is no place for such a saw, mini-saws are simply irreplaceable: a narrow blade can penetrate even into very tight spaces (for example, the gap between two pipes, one of which needs to be cut).

— Vykruzhnaya. A distinctive feature of all circular saws is a very narrow blade, one side fixed to the handle and tapering towards the end almost to the shape of a point. Due to this design, the blade is able to rotate during operation, which makes it possible to perform curly cuts. Saws are popular, in particular, in the manufacture of furniture and decorative items made of wood.

— Two-handed. Saws with a long blade length, equipped with handles at both ends; two people are needed to operate such a tool, hence the name. Two-handed saws are made only for wood and are intended for large-scale work in which other types of saws are inconvenient — for example, felling trees and sawing logs.

— Garden. A tool of this type is somewhat similar to circular and mini-saws at the same time: all garden saws are small in size and not very wide, tapering towards the end of the blade (for ease of work in hard-to-reach places). Some models can be made curved. In accordance with the name, the main purpose of such saws is relatively simple garden work — such as trimming large branches on trees and bushes that pruning shears cannot handle.

— Jigsaw. A tool colloquially referred to simply as a "jigsaw". It has the form of an arcuate or U-shaped frame in which the canvas is fixed; however, unlike the above-described bow saws (also having a frame), the holding handle lies in line with the blade. However, the main distinguishing feature of jigsaws is that the blades for them are made very narrow, which makes the tool very manoeuvrable and allows you to perform figured cuts of complex shapes. And a large distance between the canvas and the opposite edge of the frame allows you to move away from the edge of the part for a certain distance (although it usually does not exceed 20 – 30 cm). Jigsaws can be used to work on wood (plywood), metal, plastic, etc.

— Plywood. Saws designed, in accordance with the name, for sawing plywood. At the same time, unlike the jigsaws described above, plywood saws are designed not for figured, but for “rough” sawing — cutting plywood sheets in straight lines. Outwardly, such tools are similar to passer tools (see above) — they also have a wide blade and fine teeth to ensure an even and clean cut in thin material. At the same time, the front part of the blade for saws of this type is usually rounded. The teeth are sharpened in such a way as to effectively cut both along and across the fibers (individual layers in plywood have different directions of fibers, and otherwise effective sawing would be impossible). Also, such tools may have additional teeth at the end of the blade, which makes it possible to start cutting from the middle, and not from the edge of the sheet.

— Groove. Saws designed for sawing narrow grooves. In such work, high accuracy is required, therefore, in terms of the design of the blade, tools of this type are similar to slippers (see above): the blade has a rectangular shape and a rather large width, and the teeth are small. Grooving saws are also well suited for working with a miter box and can even be equipped with one (see “Miter box included”). Their most notable difference from the passers is the design of the handle: most models do not have a D-shaped handle, but a cylindrical (or similar) handle located on the butt line or slightly above or to the side of it. Due to this, work productivity decreases, however, accuracy increases and the likelihood of “cutting too much” decreases, damaging the workpiece. D-shaped pens can also be found, but they are also designed with precision over performance. In addition, the blade of a slotted saw is somewhat narrower and shorter than that of a pass saw.

— Japanese. Tools copied from traditional Japanese saws. Among these tools, two main design options can be distinguished. The first involves a handle that is noticeably bent down relative to the canvas; such a handle can be D-shaped or simple, cylindrical. The second option is a cylindrical handle mounted directly on the line of the butt or the middle of the blade. The canvas itself in both cases can have a uniform width along its entire length or expand towards the end; it is often made flexible, which gives additional features and provides convenience for some specific types of work. However, the most striking distinguishing feature of Japanese saws is that the teeth in them are bent back towards the handle. Thus, the main sawing is carried out when moving "toward yourself"; this allows you to make the saw blade as thin as possible without the risk of deforming it during operation, due to which many Japanese saws allow sawing even with a bend in the blade. In addition, it is believed that the reverse stroke provides increased accuracy compared to the classic version, “from oneself”. In addition, the teeth are usually quite small — most often at least 9 TPI, and in many models — 18 – 19 or even more; although there are coarse-toothed blades for 4 – 6 TPI. And some Japanese saws have mutual sharpening, on both sides of the blade (for more details, see "Double-sided blade").

— Chain. Saws, the blade of which is made in the form of a chain — separate links connected to each other by means of axes and capable of rotating relative to each other. In the working position, such a chain must be pulled — for this, handles are provided at each end; while the length of the chain, usually, allows one person to work with it. The main advantage of saws of this type can be called compactness: in the folded position, most of them can easily fit even in a more or less large pocket. In addition, when working with uneven convex surfaces (for example, cutting trees), the chain fits snugly on such a surface, which has a positive effect on the speed of work. But such tools do not differ in accuracy: the teeth can be quite small, but strictly controlling the position of the chain is not an easy task.

The material for which the saw was originally intended to work.

Each material has its own requirements for the shape and size of the teeth, the material of the blade, etc.: for example, wood allows large teeth (4 – 6 TPI, see below), but for metal they must be very small. Therefore, sawing “non-native” material with a saw is highly discouraged: at best, it will be ineffective, at worst, damage to the tool or damage to the workpiece is possible.

In addition to classic saws for wood or metal, more specific tools are also produced — for example, for drywall or foam concrete. A separate category is multi-purpose saws suitable for several types of materials (specific options should be specified separately). Note that in saws with interchangeable blades (such as bow or jigsaw blades), you can install different types of blades, adjusting them to a specific material. However, for them, the purpose is indicated by the complete canvas, and such models are considered multi-purpose only if several different types of canvases are initially supplied in the kit. In addition, “omnivores” can be saws with a non-replaceable blade having a specific design and sharpening of teeth. When choosing by this parameter, it is worth remembering that tools of the same purpose may differ in type (see above), and, accor...dingly, in the specifics of the work for which they are intended.

The ability to fold the blade and hide it in the handle allows you to make the hacksaw more compact. It is good for both storage and transportation, which allows you to call it a tourist or hiking. But, it is worth considering that such a design is subject to mechanical stress, and therefore it is often better not to perform rough cutting work with such a saw and use it as an auxiliary tool.

The total length of the hacksaw blade.

The value of this parameter is directly related to the saw type (see above). The general rule for choosing is as follows: the blade should be twice as long as the thickness of the largest workpiece that is planned to be sawn. This will provide an optimal range of motion to avoid unnecessary fatigue, and the tool, on the other hand, will not be too bulky. However, a long blade tends to spring back, so when working with hardwoods or other difficult-to-cut materials, shorter saws can also be taken. And in models with interchangeable blades (beam and jigsaw, some mini-saws), length data will be required to search for spare blades.

In general, for simple household tasks for sawing wood, a length of 280 – 300 mm is considered optimal. For a private house with a garden, simple construction work, you should pay attention to larger models — up to half a metre. And the largest two-handed saws can have a length of 1000 mm and even more. More detailed recommendations on the optimal blade length for certain tasks can be found in special sources.

Density of teeth in a complete saw blade; measured as the number of teeth per blade length inch (TPI).

The higher the TPI, the smaller each individual tooth, and vice versa. Other things being equal, large teeth allow you to cut easily and quickly, but not very accurately; small — provide an accurate and clean cut, but at the cost of increased effort and time. Accordingly, when choosing a saw for this parameter, one must proceed from the fact that in this case it is more important — speed or accuracy. In addition, the TPI determines suitability for small workpieces: the smallest allowable log thickness is considered to be a three-tooth pitch. For example, in a 9 TPI saw, three teeth will take up 1/3", or approximately 8.5 mm.

It is worth remembering that only tools of the same type and purpose can be compared by the number of teeth per inch. So, for example, in standard saws for wood, the minimum TPI value is 4, and already in passer saws — 9. The most coarse-toothed today are saws for foam concrete — they have about 1.2 – 1.8 teeth per inch; and the “record holders” in terms of density are saws for metal and jigsaws, for which the TPI value of 24 is almost the standard.

The variable pitch of the teeth in saws most often looks like this: for the most part of the blade, relatively large teeth are used, and at the very end, on the opposite side of the handle, smaller ones are located. The meaning of this design is, first of all, to make a small cut with small teeth at the beginning of work (it is more convenient), and then continue working with the main part of the canvas. The exception is some garden saws. In such tools, there can be as many as three options for the pitch of the teeth on one blade, and in these cases the saw is positioned as a tool that replaces 3 saws at once.

The presence of hardened teeth in the saw blade (in models with removable blades — at least one of the complete blades).

Hardened teeth usually have a characteristic dark coating that stands out from the base material of the blade. They have increased hardness and strength, which significantly increases the life of the hacksaw before blunting. On the other hand, it is impossible to re-sharpen a tool with such teeth — you will have to change either the entire hacksaw, or at least the blade.

The type of sharpening used in saw teeth. In fact, this parameter determines the shape of the tooth.

— Standard. The teeth of standard sharpening are usually made in a triangular shape; the only exception is saws for foam concrete, in which “standard” teeth can have rather specific outlines. Standard sharpening is quite functional and suitable for almost any application; in addition, if the teeth are not hardened (see above) and are large enough, they can be sharpened if necessary.

— Triangular. Externally, trihedral teeth can be almost indistinguishable from standard ones; however, if you look closely, you can see an additional edge — as if someone cut the tip of a triangular tooth obliquely and sharpened the resulting surface. Also, this sharpening is called 3D. It is considered to be more efficient and advanced than the standard one: in particular, the saw moves more easily in reverse and the teeth wear less on this move, which reduces fatigue and increases the life of the blade. On the other hand, trihedral blades are expensive, and it is impossible to sharpen dull teeth on your own — you need to change the saw (at best, the blade itself).

The presence of shearing teeth in the standard hacksaw blade (or at least one of the complete replacement blades).

Such teeth have a "two-horned" shape, with two tips pointing forward and backward; they are evenly distributed over the saw blade (for example, every 4 teeth for the fifth). The meaning of this function is to improve the efficiency of sawdust removal from the kerf; it is especially useful in damp wood, in which ordinary sheets tend to stick.

The type of additional coating applied to the regular hacksaw blade (if such a coating is provided at all).

- Anti -corrosion. A coating designed to protect the canvas from corrosion. The tool steel from which modern saws are made is not stainless; therefore, if the tool is planned to be constantly used outdoors or in conditions of high humidity, this feature will not hurt.

- To reduce friction. A coating that reduces the friction force of the blade against the material being cut (usually wood, since this feature is mainly characteristic of saws for this material). Such a coating performs several tasks at once: it facilitates the movement of the hacksaw, reducing fatigue, reduces the degree of heating of the blade (and its tendency to deformation) and reduces the likelihood of jamming the tool in the cut.

The ability to rotate the saw blade around the longitudinal axis.

This feature can be provided exclusively in bow saws — only their design allows you to install swivel fasteners for the blade. With the classic, direct installation of the blade, such saws are limited in terms of the depth of cut — the frame moves along the same line as the blade during operation, and at a certain depth inevitably rests on the edge of the material. But by turning the blade, you can use the saw for longitudinal cutting of long workpieces: the blade will move along the cut line, and the frame will move slightly to the side, behind the edge of the workpiece. So if you need a bow saw for work, and in the process you may have to deal with long workpieces, a model with a rotary blade will be perfect.

A blade with teeth on both sides; in other words, instead of a butt, a second cutting edge with teeth is provided in such a blade. However it is worth noting that such webs are considered bilateral only if the teeth on different sides are different; interchangeable blades for archery and jigsaws that have the same sharpening on both sides (assuming that when one side is dulled, use the other) do not belong to this category.

The presence of two types of sharpening expands the capabilities of the saw, but the specific features of such an extension depend on the characteristics of the teeth on each side. For example, in some models, teeth of different sizes are provided on each side — large for quick sawing and small for neat; in others, one side of the blade is for ripping, the other for cross cutting, etc. The specifics of the double-sided canvas in each case should be clarified separately.

The ability to store the blade directly inside the saw. As the name implies, this function is typical mainly for bow saws (see "Type") — they have a frame of sufficient size so that in its upper part (butt) it is possible to provide a nest for a spare blade or several blades. However, the matter is not limited to this: in some mini-saws and garden saws, the blade can be made retractable (like a blade in a paper knife); during non-working hours, it hides in the handle.

Anyway, this function allows you to safely store the blade (standard or spare) directly in the instrument, without the use of additional cases, cases, etc. At the same time, for bow saws, the main convenience lies in the ability to keep at least one replaceable blade on hand, and for compact saws, it is easy to carry (the tool fits easily in your pocket).

Possibility to change the bend of the butt in the bow saw (see "Type").

The butt is the part of the frame opposite the blade. Changing its bend, usually, is carried out by turning it by 180 °. Thus, the convex part of the butt turns “inward”, towards the canvas, the frame turns out to be not convex, but concave, and the overall height of the tool is reduced. This makes it possible to work in hard-to-reach places where a full-sized bow saw would not pass.

The depth of the frame in a saw of a bow or jigsaw type.

The depth of the frame is the distance from the blade to the butt of the jigsaw or bow saw (see "Type"). In practical terms, this distance corresponds to the maximum depth of cut that such a saw can make without turning the blade (if this is possible at all, see “Turnable Blade”). This characteristic is especially important for jigsaws — they rarely provide a rotary blade, and a frame that is too small can become a serious obstacle to work. Therefore, in modern jigsaws, the frame depth can reach 300 mm or more. But in the case of bow saws, firstly, a deep frame is required relatively infrequently, and secondly, many models are equipped with a rotary blade. Therefore, the depth in them is most often relatively small.

Anyway, it is worth remembering that a large depth significantly increases the dimensions and weight of the entire tool, and this negatively affects the convenience of work; therefore, when choosing, it is worth evaluating real needs and not chasing the largest possible frame.

The main material used in the construction of the saw handle.

First of all, we note that no matter what material the handle is made of, the manufacturer usually tries to make it comfortable and reliable enough to hold — so that the tool lies confidently in the hand, does not slip out and does not lead to excessive fatigue. For this, a special shape of the handle, a relief notch on the surface, etc. can be provided. Therefore, if you take a tool of approximately the same price level, there is practically no fundamental difference between the materials of the handles, and the choice for this indicator depends mainly on the personal preferences and sympathies of the user. However, each material has its own characteristics:

— Plastic. Inexpensive, easy to process and at the same time quite practical material. Plastic is resistant to moisture, has low thermal conductivity (does not “cool” the hands), its strength is relatively low, but for most cases it is quite sufficient. At the same time, such a handle (especially in an inexpensive tool that uses relatively simple grades of plastic) can crack from a strong impact and is easily scratched.

— Plastic / rubber. Plastic handles with rubber grips. Features of plastic are described above. As for rubber, it is provided mainly for the convenience of holding: this material is softer and “tenacious” than plastic, handles with overlays are less likely to slip out of the hands, and they are somewhat more comfor...table to hold. In addition, rubber is not particularly sensitive to scratches — on such a surface they are barely noticeable, or even “tighten” themselves. The combination of plastic and rubber is one of the most popular options today.

— Aluminium. Usually, bow saws for metal are equipped with aluminium handles (see "Type", "Purpose"). This material is highly durable, and weighs a little, but at the same time it is quite expensive, which is why it has not received much distribution. In terms of practical properties, it is completely similar to metal (see below).

— Metal. This category includes all metals except aluminium alloys (see above). This material is very durable and reliable, and it costs less than aluminium — although it weighs more. However, metal (without special coatings) is not very convenient for holding: they are hard and tend to cool hands at low air temperatures. Therefore, most models with such handles are a specific kind of bow saws: tools in which the handle as such is practically absent, and the back of the frame plays its role. However, occasionally there are saws with separately made metal handles.

— Wood. Classic material for handles, not losing its popularity these days; it is notable primarily for its characteristic appearance, and it is quite pleasant to the touch. However, in terms of performance properties, wood does not have any special advantages over plastic, and such a handle can cost much more. Therefore, in modern saws, wooden handles are often provided not so much for practical as for design reasons, and also as a tribute to tradition — based on buyers who prefer "classic" tools.

— Rubber. The handles usually use fairly dense and hard rubber, otherwise reliability would be out of the question. In terms of its properties, this option is similar to the combination of rubber and plastic described above, adjusted for the fact that in this case there is no plastic base. However inside the rubber handle there may be a blade shank, which plays the role of a base; however, the thickness of such a shank is small, therefore, such handles are classified as purely rubber, and not rubber-metal.

— Wood / rubber. Wooden handles with rubber pads. In general, they are similar to solid wood (see above), adjusted for the fact that soft rubber provides a more confident and comfortable hold in the hand, but at the same time covers most of the pattern on the wooden surface.

— Metal/rubber. Combination of metal base with rubber pads. For the first material, see above; for rubber, see Plastic/Rubber; we only note that the rubber coating in this case also plays the role of thermal insulation, providing comfort in cold weather.

— Aluminium / rubber. Combination of aluminium base with rubber overlays; has no fundamental differences from the “metal / rubber” option described above.

— Metal / plastic. Metal handles with plastic overlays — usually quite small, not even completely covering the handle. Plastic provides additional comfort when holding: it usually has a knurling for a secure grip, and in cold weather such grips do not get as cold on the hands as metal.

The presence of an adjustable handle in the design of the saw.

The design and adjustment features of such a handle depend on the type of saw (see above). So, in standard and garden saws, a swivel mount is most often provided, which allows you to choose the angle of the blade relative to the handle — this can be useful when working with a non-standard position of the tool, for example, sawing high hard-to-reach branches. In grooving saws, in turn, most often it is possible to rearrange the handle on different sides of the blade — this can be useful when sawing close to a wall or other obstacle. For example, if the wall is to the left of the cut, the handle should be slightly to the right of the blade, and vice versa.

The function of changing the dimensions of the frame allows the saw to work with blades of different lengths.

Saws with a special shape of the handle, which is mounted on an additional rod. This allows you to cut at a great distance from a person — very important for cutting branches at a height.

Availability of an overlay on teeths in a set of delivery of a hacksaw.

Such an overlay, in fact, is a simplified version of the cover (see below), covering only the most dangerous and at the same time delicate part of the canvas — sharp teeth. A saw with a guard installed can be safely stored and transported without fear of contact between the teeth and surrounding objects (which could lead to both damage to these objects and damage to the blade). At the same time, the pads are more compact and cheaper than full-size cases.

The presence of a ruler in the design of the hacksaw.

Usually, this ruler has the form of a scale printed on the butt of the blade. It hardly makes sense to use it all the time as a replacement for a regular ruler, however, having such a scale on hand can be very useful if you need to quickly measure the length or draw a line (for example, control the size of the cut or extend the markup on the workpiece), and others There are no metres nearby.

The presence of a cover in the scope of delivery of a hacksaw.

The cover will be useful for storing and transporting the tool: it closes the saw almost entirely (there is usually only a handle outside), protecting the blade and frame (if any) from dirt, moisture and contact with foreign objects. The latter allows you to safely carry the saw in the same bag with other things. Regular covers, usually, are much more convenient than improvised devices (like a rag in which the canvas is wrapped), and are generally inexpensive.

Availability of additional replaceable cloths in a set of delivery of a hacksaw.

Usually, in this case we are talking about a bow or jigsaw model (see "Type"). Options for such a configuration can be very diverse: “purely spare” blades (of the same type, with the same tooth size), “different-sized” (of the same purpose, but with different tooth sizes), for different types of materials, etc. And the number of interchangeable sheets can be different, so the features of the kit in each case need to be specified separately. However, anyway, the purchase of such a set can eliminate the need to purchase additional canvases, thus saving time and effort.

The presence of a miter box in the scope of delivery of a hacksaw.

The miter box is a device for precise sawing of workpieces at certain angles. It has the form of a trough, in the sides of which narrow slots are made; a workpiece is placed in the groove during operation, and the slots act as guides for the saw (usually they are directed at angles of 45 ° and 90 °, although more options may be provided). Cutting in the miter box is carried out with a pass saw (see "Type"); accordingly, it is this type of saws that can be supplied in this configuration. However complete miter boxes are usually relatively simple devices made of inexpensive materials; for professional work, you may still need to purchase additional equipment.