Comparison Bahco PC-9-9/17-PS vs Bahco 3150-12-XT9-HP

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 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 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 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.