Since the moment the term “power tool” is in the vocabulary of modern man, a circular saw is firmly on the list of most popular tools. We must note, however, that since a saw blade was placed on the motor shaft, there has been no single fundamental change in the design of this tool. All improvements were aimed purely at achieving more safety. In this circular saw buying guide, we will pay attention to those important criteria that must be taken into account when choosing a circular saw that fully meets your needs.
Circular Saw Usage
Initially, a circular saw was a purely stationary tool – in fact, it was a machine for industrial woodworking, consuming thousands of kilowatts of energy with a weight of hundreds of pounds.
The portable version came to the market in the middle of the last century and has since been improved mainly in the automation of the cutting process and development of new security systems. With new types of discs, today a handheld circular saw can cut not only wood and its derivatives (plywood, chipboard, MDF, OSB), but also much more solid and denser materials – different types of plastic, laminate, and slate. A hand saw can also cope with some types of sheet metal if a shaft is fitted with a special-purpose notched disk.
A circular saw has also limitations in its usage. Firstly, it can be cut only strictly straight (this is very useful sometimes). Secondly, a circular saw usually can not handle solid materials such as brick or concrete, unless this model is equipped with a diamond disc and a water cooling system. However, in practice, the hardest materials can be cut by angle grinders (USM) and a circular saw is used for cutting wood. The latter has a very high performance.
Circular Saw Characteristics
The key characteristics of a circular saw are its power, rotation speed, and depth of cut. The latter directly depends on the diameter of the disc, supported by this type of saw.
We should note that for handheld circular saws, dividing into professional and household groups is perhaps even more conditional than for any other power tool. After all, the need for a hand disk saw arises when cutting wood quite often and this means that cutting boards, plywood, chipboard, most likely are part of daily work.
The depth of cut
According to the cut depth, circular saws can be divided into three main categories:
- 40-50 mm – household saws for working with sheet materials;
- 50-65 mm – multi-purpose saws for most works;
- 65-140 mm – professional models, for specialists whose work is related to construction with the use of wood.
Circular saws with a cutting depth of 55 mm are usually fine for most DIY projects – both of the repair and construction.
The higher the disc rotational speed, the denser material can be cut. The rotation speed of a household tool is usually from 1500 to 4500 rpm. The professional one – from 2000 to 9000 rpm.
The power consumption of relatively simple models is about 600 watts. Professional models have a power consumption of 2-2.5 kW or more. More powerful saws also weigh much more than less powerful models. If a saw with a power of 1.2 kW weighs an average of 9 lbs, the weight of a two-kilowatt tool is about 15 lbs. So it’s up to you if purchasing a more powerful saw is reasonable to you.
Most circular saws can cut at an angle of 45 degrees. The design of some models also allows sawing at an angle of 60 degrees.
Most of the developments implemented in the latest generation of circular saws are aimed at ensuring no accidents at the saw usage. As for the number of additional settings, it is increasing every year.
One of the important functions is a smooth start. It allows avoiding overloads and overheating of the engine, as well as a sudden increase in the current in the network system. It is also important to remember that at starting, the disk should rotate freely and not touch the material for cutting, otherwise the saw will simply not be able to speed up enough.
The most complex models have a function called “constant electronics”. It is aimed to withstand the optimum ratio of the rotational speed and power output to the shaft. Thus, jamming the disk is prevented. It also affects the cut quality. But implementing such a function requires a sufficient supply of power.
Top models are also protected against overloads, for example, in the case of too much eagerness of a saw operator. In this case, the automation will turn off the power and thus save a saw owner from an unplanned repair.
And finally, there is a function called electrodynamic braking. This system launches the moment a saw operator releases the power button and immediately stops the disk, thereby reducing the probability of an injury.
There is also a device called a “slip clutch”. It works when the disk is stuck in the billet. In this case, the clutch releases the motor shaft and it keeps rotating freely to avoid the burnout of motor windings.
Circular Saw Quality Criteria
As we already mentioned, the most important criterion of a handheld circular saw quality is its potential safety. Today, there is no circular saw without automatically closing the spring-loaded casing. This construction makes hand injuries during the saw usage almost impossible. It is great if a saw also has a function protecting from accidental triggering. This is ensured by an additional button to be pressed at the same time as the main button to start the disk.
In many respects, the circular saw efficiency depends on the quality of its support plate. It is this plate that all adjusting mechanisms and fasteners are installed to. The best are platforms made by casting aluminum-based alloys. But platforms, stamped from special grades of steel have also good feedback. They are resistant to impact loads and do not increase the product cost too much.
Other circular saw quality criteria include a reduced vibration level and a stabilization system. The cord length is also important. As the main tool operation is lengthwise cutting, the cord length must let you move freely at a distance of 120-160 inches. Even better, if your model runs on battery power. This can be very useful, especially when working at heights.
Important to Remember
A handheld circular saw is not the safest tool, therefore, even despite all safety measures undertaken by manufacturers, there is a small risk of injury. So, we want to supplement our circular saw buying guide with some minimum safety rules when using this tool.
- Strictly follow the safety measures specified in the instructions.
- Be sure to use glasses for protection from dust particles of wood or other material.
- Always hold a saw with your both hands and the cut object must be securely fixed. One of the typical unpleasant moments when using a circular saw is jamming of the disk in the billet, which can lead to engine overheating and an unpleasant phenomenon called a kickback. To avoid this, select the correct cutting disc – it must correspond to a specific material.
- The material for cutting must have no foreign objects (nails, remnants of metal fasteners).
- The saw must also not overheat.