Comparison Sturm CC9920CLM vs Grand APC-20V/4 Professional

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.

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.

- Disc. The presence of a saw blade is included in the delivery set of the circular tool. It can be either one or several, which allows you to use the saw “out of the box” without the need to purchase additional consumables. If you already have a saw blade or intend to select it for specific tasks, it is worth taking a closer look at the configurations without a blade - they are usually cheaper.

- Chain. One or more chains included as standard with the saw. The presence of a chain with teeth for cutting allows you to do without purchasing a separate executive body for chain saw. However, there are configurations without a chain - it is assumed that the customer already has a chain or he will select the required option himself.

— Saw blade. The presence of one or more saw blades in the complete set of a reciprocating or band tool. They ensure that the saw is ready for use literally immediately after unpacking. There are also configurations of reciprocating or band models without a saw blade - they are cheaper, and the customer has the right to choose a suitable blade independently.

— Dust collector. A dust collector is included with the saw. The dust collector is a container for collecting sawdust and other d...ebris generated during operation; As a rule, such a container is made removable. Installing a dust collector slightly increases the dimensions of the entire tool, but this is compensated by cleanliness and convenience: dust and other production waste mostly settle in the container and not on surrounding objects.

- Charger. The presence of a charging block in the package allows you to charge batteries. Accordingly, for models with batteries, this accessory is necessary to power the battery. However, there are models without a charger. And saw with it may differ in the charger model, the name of which will allow you to learn more about its characteristics and, if necessary or if required (breakdown), purchase a similar one.

— Case (bag). Availability of a case or bag included with the instrument. A case is a container-suitcase made of hard material; bags are usually made of soft material. This way the case provides maximum protection and the bag can be folded away compactly when not in use. The specific type of case that comes with the saw should be specified separately. However, in any case, a complete case or bag will be more convenient for storing and transporting the instrument than impromptu packaging.

- Stand. The stand makes the saw tool more stable, reliable and safe. The presence of a stand is typical for stationary type saw. Mostly these are powerful, productive, large and heavy models that are located in a separate place. The stand can be implemented either with classic legs (bed) or with a cabinet with a tool compartment. The stand can be equipped with various types of saw: circular saw, miter saw, band saw, cutting saw and even chain saw (with electric drive).

— Wheels for transportation. Transport wheels make it easy to move sawing equipment around the shop. The presence of wheels will come in handy when the saw needs to be moved a little to install some large workpieces or simply when cleaning the workshop. As a rule, wheels are typical for stationary saw with a table top or work holder.

Features of the battery saw package, regarding the presence of a battery in the kit or the design of the tool. For cordless tools in general, see "Power Source", and the options in this case may be as follows:

— Missing. The complete absence of batteries in the delivery set — they need to be looked for separately. This is associated with certain troubles, but it also provides important advantages. Firstly, the model and number of purchased batteries can be chosen at your discretion, depending on your needs and low-cost. Secondly, a suitable battery may already be “in the household” — especially when you consider that some manufacturers produce universal batteries suitable for different types of power tools of the same brand. Thanks to all this, this option is extremely popular — in fact, most cordless saws come without batteries.

— 1 battery. "Classic of the genre": one removable battery included. The main advantages of this configuration are low cost and at the same time the ability to use the saw “out of the box” without selecting power sources for it. At the same time, when the charge is exhausted, you will inevitably have to take breaks for charging — or still buy another battery. Thus, this option is relatively rare — sets with two batteries are more common.

— 2 batteries. The most popular option among saws supplied with batteries included. H...owever, it is worth noting that in this category there are two types of tools. The first, and most common, is saws for one battery. In such models, the second battery plays the role of a spare, its presence allows you to extend battery life and minimize interruptions for charging: while one battery is in use, the second can be charged. The second variety of saws in a similar configuration are models that initially operate on two batteries (see "Powered by two batteries") and are supplied with power supplies in the kit; this case is analogous to having one battery in a simpler tool (see above).

— 3 batteries. A very rare configuration option: in the presence of a charger for 2 batteries, it allows you to practically eliminate interruptions in charging, but it is expensive and rarely needed (and in cases where 3 batteries are really needed, the required number of batteries can be purchased separately).

— 4 batteries. A variant found among individual models powered immediately by 2 batteries. Essentially the same as 2 batteries for a tool powered by 1 battery; see above for details.

— Built-in. A battery built into the body of the saw and not designed to be removed and replaced by the user. This design somewhat reduces the overall dimensions of the tool, but does not allow you to quickly change a dead battery to a fresh one — the only option is charging, which can take quite a lot of time. In addition, if the battery fails, the tool will, at best, have to be carried to a service centre, at worst, replaced with a new one. Therefore, this option is used extremely rarely — in separate low-power tools that are not designed for high loads and long-term operation.

The name of the battery platform supported by the device. A single battery platform is used to combine various power tools of the same brand into one line (screwdriver, grinder, circular saw, etc.). Devices on the same platform use interchangeable batteries and chargers. Thanks to this, for example, there is no need to select a battery for each individual model of a power tool, because one purchased as a spare battery can be used in various power tools, depending on the situation or as needed. Batteries of the same platform basically differ from each other except perhaps in capacity.

The type of battery installed in the battery-powered tool (see "Power Source").

— Ni-Cd (nickel-cadmium). The most "old" option found in modern power tools. It is distinguished by high reliability, resistance to temperature extremes and good charging speed even with high capacity (which is important, given the "voracity" of the power tool). The main disadvantage of this type of batteries can be called a pronounced "memory effect" — a decrease in battery capacity if it is set for charging without being completely discharged. In addition, Ni-Cd cells are considered environmentally unsafe. Nevertheless, they are still widely used in tools — not least due to their low cost with decent performance.

— Ni-Mh (nickel-metal hydride). Such batteries were created as a development of the nickel-cadmium batteries described above. Retaining all the main advantages of their predecessors, they are at the same time devoid of most of the shortcomings — in particular, they are practically not subject to the memory effect. Of the own shortcomings of this option, it is worth mentioning a slightly lower durability and higher cost than the original Ni-Cd.

— Li-Ion (lithium-ion). A type of battery originally developed for use in portable devices; however, with the development of Li-Ion technology, it has also been used in power tools. The main advantage of such batteries in this case can be called a high capacity with small dimensions an...d weight. It is also worth noting that they are not subject to the memory effect and are able to charge quite quickly. On the other hand, this option is not without its drawbacks — this is, first of all, sensitivity to too low or elevated temperatures, as well as a high price.

The capacity of the battery supplied with the saw of the corresponding type (see "Power source").

Theoretically, the higher the capacity, the longer the tool can work without recharging / changing the battery. However, in fact, things are not so clear cut. Firstly, the actual battery life depends not only on the characteristics of the battery, but also on the power consumption of the tool (and it is directly determined by the power of the engine). Secondly, only batteries with the same nominal voltage can be compared in terms of capacity in ampere-hours; if the voltage is different, ampere-hours must be converted to watt-hours using special formulas and the results already obtained should be used. So it makes sense to compare by this parameter only saws with the same battery voltage and similar engine power. And to assess the actual battery life, it is better to pay attention to the indicated operating time and/or the number of cuts (see below for both).

Note that many models allow you to work with batteries of different capacities — it is enough that they are compatible in terms of connectors and operating voltage.

Battery models that the saw of the corresponding type is compatible with (see “Power source”). This information will be useful in cases where the battery(ies) must be purchased separately, for example, if the tool does not come with a battery at all, if you need to supplement the original package, or if the existing battery has failed.

The time required to fully (from zero to 100%) charge the battery in the cordless saw (see "Power supply"); this refers to the complete battery and standard charger. The shorter this time, the shorter the breaks will have to be done for recharging; however, higher capacity batteries inevitably take longer to charge than smaller ones. This can be compensated by the use of fast charging technologies, but they, in turn, affect the cost of the tool.