No load blade speed
The maximum speed of the disk, provided by a saw of the appropriate design — disk, cut-off, etc. (see "Device").
Note that most of these saws use gearboxes, so that the blade revolutions are much lower than the engine revolutions (see above). This achieves an increase in torque, which in the case of saws is often more important than the high speed of the blade.
As for the specific number of revolutions, it is first of all worth noting that only saws with the same disc diameter can be compared according to this indicator. In these cases, higher speeds provide better performance, but the trade-off is reduced torque; such saws do better with relatively "light" materials. Conversely, low speeds reduce productivity, but allow the blade to effectively "bite" even into dense, stubborn workpieces. More specific recommendations regarding the choice of a saw according to the number of revolutions of the blade can be found in special sources.
Bore diameter
The diameter of the mounting hole for which the blade holder in the saw of the corresponding design is designed (see "Device"). In fact, this paragraph indicates the diameter of the axis on which the disk is installed — this size should correspond to the hole in the disk itself.
Note that some models of saws allow the installation of discs with larger holes than indicated in the specifications — when using an adapter sleeve. The main thing is that the own diameter of the disk does not exceed the values \u200b\u200ballowed for this model (see "Tyre / disk diameter"). Popular sizes include
20mm,
25mm and
30mm.
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).
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.
