Engine size
The volume of the engine of a gasoline saw (see "Power source"). On the one hand, the power and performance of the tool depend on this indicator, on the other hand, its weight, price and fuel consumption. Accordingly, it is necessary to choose a model taking into account the specifics of the planned work, and it does not always make sense to chase large volumes. In particular, for simple household tasks, an engine capacity of about 40 – 50 cm3 is considered quite sufficient, and in professional models this figure can exceed 100 cm3. More detailed selection recommendations can be found in special sources.
Power
The power of the saw engine expressed in horsepower (hp). This designation is traditionally used in gasoline models (see "Power Source") along with watts; 1 HP ≈ 735 W.
For more information about power, see the paragraph of the same name above.
Idle speed
The speed of rotation of the engine in a saw with an internal combustion engine (see "Power") with no load on the blade and with the speed controller fully released (set to minimum). Theoretically, the lower the idle speed, the lower the fuel consumption without load (ceteris paribus); however, the difference between modern chainsaws is usually so insignificant that this parameter is more of a reference than a real practical value.
No load speed
The highest speed that the saw engine is capable of delivering in normal operation.
We emphasize that this parameter should not be confused with the maximum disk speed (see below) — here we are talking exclusively about the speed of rotation of the motor shaft. It can be specified for all types of saws, not only for models using discs. However, in general, engine speed is more of a reference than really significant information. In fact, it is needed mainly for some specific tool maintenance tasks; when choosing, it is better to focus on indicators that are more “close to life” — engine power, cutting depth, chain / tape speed or disk speed, etc.
Chain speed
The maximum speed of the chain relative to the material that a saw of the appropriate design can provide (see "Device"). Higher speed allows to achieve faster and cleaner cuts, but requires more engine power; low speed, in turn, reduces productivity, but allows you to achieve good traction with a relatively low engine power. More detailed recommendations regarding this parameter can be found in special sources.
Noise level
The noise level produced by the saw during operation. Note that this parameter is rather approximate, because in fact, the “loudness of the work” depends not only on the tool, but also on the material being processed and the characteristics of the environment. Nevertheless, the data given in the characteristics make it possible to assess the comfort of working with the tool. The lower this indicator, the less discomfort the noise will cause, and at high values, even special hearing protection may be needed.
Note that the noise level is usually measured in decibels, and this unit is not linear: for example, a difference of 3 dB corresponds to a difference of 2 times, 10 dB — to 10 times. Therefore, it is easiest to evaluate the noise level using comparative tables. Here is a simplified version of such a table for the range in which modern saws operate:
70 dB — loud conversation of several people in close proximity;
75 dB — a cry in the immediate vicinity;
80 dB — truck engine, mechanical alarm ringing;
85 dB — loud scream;
90 dB — freight car at a distance of 7 – 10 m;
95 dB — subway car at a distance of 7 – 10 m;
100 dB — industrial shop;
110 dB — tractor engine;
120 dB — demolition hammer, thunder from a close lightning strike (pain threshold of auditory perception).
Fuel tank volume
The volume of the fuel tank in saws with a petrol engine (see "Power source"). A volume tank, on the one hand, allows the device to work for a long time without refueling, on the other hand, it seriously affects the weight and dimensions. The latter is not critical for stationary units (see "Type"), but it is very important for portable equipment — and the vast majority of chainsaws and power cutters are made portable. And taking into account the fact that refueling usually does not cause any particular difficulties, it does not make sense to equip hand tools with capacious tanks, therefore this volume is small in such saws.
Oil tank volume
The volume of the oil tank provided in the tool.
In this case, we mean a tank from which oil is supplied to the saw chain (see "Device") to lubricate it during operation. In general, this is a reference parameter that allows you to estimate how much oil is needed for one refueling of the tool.
Weight
The total weight of the tool. For petrol models (see "Power Source"), usually, dry weight is indicated, excluding fuel.
In general, it makes sense to pay attention to this parameter primarily when choosing a hand tool. At the same time, note that higher power, a more capacious battery or a capacious tank will inevitably affect weight. However, tools with similar characteristics can and do differ markedly in weight. And here it is worth considering that a lighter model will be more comfortable to work with, but weight reduction may affect reliability and/or cost. In addition, a more massive tool is more stable, it is not so prone to jerks under uneven loads. If we talk about specific numbers, then a weight of
3 kg or less is considered very light,
3–5 kg is relatively small,
5–7 kg is medium,
7–10 kg is significant, and some powerful tools (mainly gasoline) weigh and
over 10 kg.
As for stationary saws, weight is of secondary importance for them — it mainly affects the ease of transportation.
