A circular saw is an indispensable assistant for a zealous householder. A wide range of operations performed imposes a great responsibility when choosing a tool. Let’s talk about how not to make a mistake today.
In general, a circular saw (in everyday life, a circular saw is more often used) is a power tool for sawing wood materials, in which the cut is carried out by a special cutting disc with teeth rotating at high speed. When using special discs, it is possible to cut not only wood materials, but also metal or ceramics. The peculiarities include the fact that sawing is carried out only in a straight line.
What are circular saws
The classic circular saw (with a transverse engine) is the most common and well-known option. Wide range of dimensions, different power range, disk rotation speeds, etc.
Mini circular saw — looks like an angle grinder. Due to their modest dimensions, they are distinguished by low power, low weight, but great convenience — you can work with one hand, in horizontal and vertical planes, at an angle, on weight or in confined spaces.
Plunge saws — used for high-precision sawing of materials, while it is absolutely not necessary to start sawing from the edge of the workpiece, as with other saws. Due to the special structure of the mechanism, the disc is located above the platform and, justifying its name, “is immersed” in the material being cut in the right place.
In most cases, these saws are used with special guide rails for maximum precision when sawing. Used for sampling grooves, holes and processing the ends of workpieces.
Hypoid saws are similar in size and purpose to classic saws, but in them the engine is located parallel to the plane of rotation of the disk, due to the hypoid gear, which is more convenient. Another distinctive feature is that the saw blade is located on the left side.
Also, despite the fact that the saws were originally powered by AC, at the moment there are many models that use a battery as a power source. Network models are more powerful, but also bulky, while battery models are lighter, more convenient and portable.
In addition to the above options, there are models for stationary installation, used as small saws.
Key Features of Circular Saws
Let’s move on to the main characteristics / criteria for choosing a circular saw.
Circular saw power
The main characteristic of the tool that affects how dense / hard and thick materials the saw can cut. According to this criterion, several groups can be distinguished (although the division, in general, is a bit arbitrary):
— up to 1000 W — small tools, for example, for apartments, for working with sheet wood materials: OSB, plywood, chipboard. As well as laminate, softwood boards;
— from 1000 to 1500 W — more powerful and versatile tools, designed to work with various wood materials, whether it be timber, logs, thick boards from various types of wood, as well as metal (when using a special disk);
— over 1500 W — it is considered to be the lot of professional models that work with all materials acceptable for circular saws and a much longer duration of work without interruption.
The speed of the sawing process will depend on this parameter. Other things being equal, a faster tool model will give higher performance i.e. faster cut. In most cases, the rule works — high power — high speed. However, there are also low-power models with a high rotation speed.
In the direct sawing process, depending on the hardness (density) of the workpiece being processed, the frequency will decrease, up to the stop (jamming) of the disk, and in such a situation, a large engine power will prevent this to a greater extent.
Depth of cut (at an angle of 90°)
First of all, it depends on the diameter of the working (saw) disk and the design features of the saw, and secondly, as already mentioned, on the power of the saw. Household models up to 800-1000 W will be content with 40-45 mm sawing depth, universal ones with a power of 1000-1500 W increase this figure to 50-65 mm, and powerful professional models even up to 85 mm or more.
Scale for setting the blade offset (behind the saw handle)
It should be remembered that this indicator is the maximum value. All saws allow adjustment of the sawing depth using a special mechanism. This is a very useful feature that should not be neglected, for example, when sawing thin sheet materials. In such cases, the performance will be higher, and the heating of the disk is less, and the load on the engine is lower.
Changing the angle of inclination
Most of the manufactured circular saws can perform sawing not only perpendicular to the surface of the workpiece being processed (i.e. at an angle of 90 °), but also change the angle of the blade. In most models, this angle is limited to 45°. The maximum thickness of the part to be sawn is, of course, reduced.
Let’s pay attention to the main working «tool» — the saw blade. Little by little, the disk wears out, and, sooner or later, the question of replacing it will arise. The main parameters are the outer diameter and the diameter of the mounting hole, determined by the design of the saw — both of these values \u200b\u200bare important when choosing a blade.
To avoid injury, do not use discs with an outer diameter less than or larger than the standard diameter.
The choice for the intended purpose will be the second condition and will depend on the material being cut, and the requirements for the quality of processing the edges of the cut. For example, for fast sawing of wooden boards, bars, a blade with fewer teeth is recommended. If you need a “clean” cut, without chips, then the number of teeth should be the largest.
Also on the packaging, manufacturers indicate what materials this disc can work with. This is due to different teeth in shape and frequency for different materials and speeds.
Additional functions of circular saws
Connecting a vacuum cleaner or a bag — all models in the protective casing have a hole for ejecting chips. The manufacturer can supply the tool with a special cylindrical nozzle, to which you can connect a construction vacuum cleaner or a sawdust bag, which makes the workflow less dusty.
Spindle lock — allows you to fix the disk from rotation, for example, to replace it.
The presence of a level — for cutting along a predetermined line, a special mark on the sole of the tool is used. Unfortunately, the accuracy and evenness of the cut in this case does not always turn out to be necessary.
The laser level releases a beam in front of the tool along the plane of the disk, allowing you to keep the ideal trajectory of movement, exactly along the intended line, from the beginning to the end of the sawing process.
Soft start — for models equipped with a soft start when turned on, there is a uniform set of revolutions, which eliminates jerks of the tool, reduces the load on the network at the time of start and prolongs the life of the engine.
Speed control — to work with different materials, you need not only different saw blades, but also different operating modes. Allows you to set the most suitable rotation speed based on the blade used and the type of material being cut. A useful feature, but not available to budget models.
Electronic motor protection — will protect the saw motor from premature failure, when the blade is jammed, during operation.
Electrodynamic brake — quickly stops the rotation of the engine after releasing the start key. There is no need to wait 5-10 seconds for the drive to stop. There is not much security.
The presence of a riving knife is located behind the saw blade and prevents it from being clamped when sawing along the fibers.
Parallel stop — designed for sawing parallel to the side surface of the workpiece. To set a certain width, graduation is applied on the stop ruler.
The possibility of stationary installation — with the help of special mounts, some models can be fixed to a table or workbench and get a kind of sawing machine, for this their body is beveled at the top. More common in professional, powerful models. It is only necessary to make sure that the fasteners themselves are reliable, since they bear the main load.
For a battery-operated tool, additional criteria can be distinguished:
- Battery capacity — the larger the capacity, the longer the tool will work (ceteris paribus).
- Battery Voltage — Higher voltage means more saw power and longer battery life.
- Battery type — One of the trends in modern cordless tools is the use of lithium-ion (Li-Ion) batteries. The advantages of lithium-ion batteries include high cell capacity (fewer cells are required), no memory effect (no need to completely discharge before charging).
Among the shortcomings, one can note the loss of capacity at low temperatures (do not work much in the cold). But nickel-cadmium (Ni-Cd) battery models have not completely disappeared, and they can also be found on sale.
The batteries on them are slightly heavier (there are more cells inside), to prevent premature failure, they must be completely discharged before charging, but they better withstand low temperatures, allowing you to work, for example, in winter.
The number of batteries included — sometimes stopping work, for example, from an untimely discharged battery, is highly undesirable. To avoid this, some models are equipped with several batteries. This of course increases the cost of the tool, but it can also help you out more than once.
For their own produced cordless tools, manufacturers offer the use of the same (in terms of size) batteries, creating a certain “ecosystem”. For example, the same battery can be used for a circular saw, jigsaw, screwdriver or angle grinder.
Help in choosing a circular saw
When choosing a saw for small amounts of work with sheet wood materials, soft woods of small thickness, opt for models 600 — 1000 W, and cutting depth up to 45 mm. It will be a light, handy and inexpensive saw.
For working with small workpieces, for working in cramped conditions, in a vertical position or on weight, look at corded or cordless mini circular saws. Such models will allow you to work in hard-to-reach places where a large tool simply does not fit.
«Universal» 1 — 1.5 kW models are suitable for private households, owners of gardens, summer cottages, performing various types of work — making a fence, building a barn or porch / gazebo, repairing the roof, etc. For example, with a tool with a sawing depth of up to 65 mm, it is possible to saw thick boards on the floor / frame / rafters and dissolve them into bars.
Professional, heavy models with a power of around 2 kW are used in repair and construction, where long continuous operation, high reliability and resource are required, as well as work not only with wood, but also with metal.
Plunge saws are suitable for work that requires high precision and fine sawing, for grooving. For example, when making furniture, cutting holes, etc. They are not always highlighted in a separate view, so you have to search manually by appearance.
Sometimes it is more convenient to process workpieces on a stationary machine; for this, there are models for stationary installation. They can either be mounted on a table / workbench, or have legs for installation directly on the floor.
The exact opposite of stationary saws is cordless models. Sawing various materials is no longer tied to an outlet, which is convenient in many cases — for example, when building roofs. But the price of such models is higher, and autonomy reaches only a few hours.