Comparison Black&Decker KA88 vs Black&Decker KA86

Belt speed provided by the grinder. For more information about belt units, see "Type". In this paragraph, both one value and a range can be given — if the device has a speed control (see "Additionally — Speed regulator").

Other things being equal (primarily the same belt width), a higher speed has a positive effect on productivity. On the other hand, to ensure such a speed, a more powerful engine is needed, which accordingly affects the weight, price and energy consumption of the entire tool. In addition, the low belt speed contributes to accuracy: the chance of removing excess material is reduced. So it’s definitely worth looking specifically for a “fast” grinder only if it is to be used often and for large volumes of work. In other cases, a slower model may well be the best option. More detailed recommendations on this matter (including for different materials and types of work) can be found in special sources.

The length of the belt or sheet for which the grinder is designed.

Working nozzles in the form of sheets are used in units with a vibrational principle of operation, in the form of tapes — respectively, in tape ones (for more details on both, see "Type"). Anyway, this paragraph does not indicate the working length of the tape / sheet (that is, the length of the surface adjacent to the material being processed), but the total — that is, the size of the nozzle itself. This size in itself determines only the compatibility of the grinder with certain sheets / tapes. At the same time, clamp-like fastenings (see "Sheet fastening"), used in most classic vibrating instruments, often allow you to install sheets of slightly longer lengths than indicated in the specifications. Hook-and-loop models (mostly delta sanders) technically accept both longer and shorter sheets, although in fact this is not recommended at best. But in tape tools, the length of the tape must exactly match the parameter specified in this paragraph — even a slight deviation can lead to incompatibility.

As for the working length of the tape / sheet, it inevitably turns out to be less than the total (for sheets — not much, for tapes — quite significantly). However a longer tape/sheet often has a greater working length; however, with the same general dimensions of the nozzle, its working size in different tools may be different; it is indicated in the item "Sole Size" (see below).

The size of the sole provided in the tool.

This parameter is indicated for two types of grinders — most models with a vibrational principle of operation (namely, for vibration and delta grinders, as well as multifunctional ones), as well as belt units. For more information about both, see "Type", here we note that the sole as such is only available in vibrating tools — in tape tools, we are talking about the size of the section of the tape that is in direct contact with the material. Simply put, the size of the sole is the size of the working surface of the machine.

The larger the size of this surface, the more performant the machine, the better it is suitable for large volumes of work. And tape models, we recall, are used mainly for processing oblong parts and during operation they are usually located across such a part; so that for such machines it is highly desirable that the length of the tape be not less than the width of the surface to be treated — otherwise, accurate processing can be quite difficult. On the other hand, a large sole inevitably affects the dimensions, weight, and most often the cost of the tool, besides, it can make it difficult to use in cramped conditions. Yes, and consumables for such soles (sheets, tapes) require larger ones — and, accordingly, more expensive. So when choosing according to this indicator, it is worth considering the features of the intended application; if you wish, you can refer to special sources for detailed r...ecommendations on this matter.

Also note that for multifunctional models (see "Type") in this paragraph, several options are most often given — for each specific sole. However, there are models where only one set of sizes is indicated. This can either mean that both main vibration nozzles (rectangular and triangular) have the same dimensions in length and width — or that the data is indicated for a non-removable triangular sole, on which a larger rectangular one is put on if necessary. Such details can often be clarified directly from the photographs of the goods, in extreme cases — from the manufacturer's documentation.

— Additional Handle. A separate handle for the second hand. In theory, such equipment may make the tool more comfortable to hold with both hands. However, in practice, the absence of an additional handle is often not critical: many tools without it are either designed for one-handed use (like some straight grinders, see "Type") or have other attachments for the second hand (such as a protrusion on the body). So, to answer whether you need an additional handle, you should consider the type and size of the grinder, as well as the specifics of the intended projects. Note also that by default, such a handle is designed for right-handed use, and the possibility of using it in left-handed operation needs to be clarified separately.

— 3-Position Additional Handle. An additional handle installed on a detachable mount and having three installation options: on the left (traditional option for right-handed use), on the right (for left-handed use), and on top (for specific cases — situations when you need to periodically change grip, work in hard-to-reach places, etc.). This function provides extended possibilities for tool customization according to personal preferences. It is mainly found in angular models (see "Type").

— Charger (C). A device for charging the battery in a grinder with the appropriate power type (see "Power Source"). This section usually specifies...the specific model of the charger. Having a "charger" included relieves you from the need to search and purchase it separately; moreover, such a charger is optimally suited at least to the "native" battery, and often to other compatible batteries. The details on the model will be useful primarily in case the included charger is lost or fails, and you have to buy the same or a similar one instead. Moreover, knowing the model of the charger allows you to find detailed data about it and assess the characteristics and features (compatibility with various batteries, additional functions, etc.). At the same time, the configuration "without charger" is also quite popular — see below.

— Without Charger. This feature is indicated exclusively for battery models (machines with other power types — see "Power Source" — by definition do not have a charger, so this point does not need to be clarified for them). The meaning of such a configuration is that modern grinders most often use standard batteries, which also fit other power tools of the same brand and are thus designed for standard "chargers." Thus, if there is already a battery tool "in the household" — the charger for it may turn out to be suitable for the grinder, and you will not need to pay extra for a second copy of the charger. And even if there is no charger available — it can usually be purchased separately without much difficulty (and some tools even allow you to choose the most suitable model of such a device from several options).

— Case / Bag included. The presence of a case or bag for storing and transporting the tool in the supply kit. The case is a suitcase made of durable material and usually has space not only for the grinder itself but also for working tips and other additional accessories. The bag is soft, allowing it to be compactly folded when not needed. Check the availability of a case or bag directly before purchase.

— Dust Collector. A container for collecting dust and other contaminants generated during work. See "Additional — Dust Collector Connection" for more details.

— Extension Pole. A long pole significantly expands the "radius of operation" of the tool: with such equipment, you can reach greater heights, process a large area without moving the platform or other stand, etc. Such capabilities are mainly relevant when processing walls, so the vast majority of grinders with extension poles included pertain to wall sanders (see "Type").

Approximate noise level generated by the grinder during operation. Note that this indicator is quite approximate, because. actual "loudness" can vary markedly depending on the type and shape of the material being processed, the surface it is placed on, and other circumstances. In addition, different manufacturers may use different measurement methods. Nevertheless, this indicator makes it possible to assess how comfortable this or that model is in operation and whether special hearing protection is required.

The most “quiet” modern grinders give out about 65 dB — this is comparable to loud speech at a distance of 1 m; in the loudest, the noise level reaches 107 dB — this is the volume of an industrial workshop.

The total weight of the grinder; for battery models (see "Power Source"), usually, it is indicated without taking into account the battery.

This indicator has two meanings. On the one hand, light weight has a positive effect on manoeuvrability and reduces fatigue during work — especially when processing vertical surfaces and ceilings, as well as in other situations where the tool has to be held on weight. On the other hand, for grinders with a vibrational principle of operation (see "Type"), used for processing horizontal surfaces, a significant weight is considered optimal: it allows the tool to fit closer to the material being processed, and also contributes to stability and retention. So when choosing such a model by weight, it is worth considering the features of its intended application.