Angle grinder (angle grinder) – aka “grinder” – is a power tool, which is a type of grinder. The set of its “functionality” includes various operations related to cutting, cleaning and grinding of parts from any materials. Scope: metalworking, construction, domestic needs.
Scope of application. Professional and household grinders
The grinder belongs to the universal use tools – this machine is capable of performing a large list of operations. True, for their various types it is necessary to change the working “organs” themselves – nozzles. Then the grinder cuts, polishes, cleans stone, metal, wood and other materials.
In everyday life, this tool is not used every day, but if necessary, you cannot do without it – the century of manual labor is a thing of the past. Angle grinder saves you time and effort.
Depending on the mode of use and power of the engine and other components, there are grinders:
- domestic use;
- industrial use.
Household “grinders” are mainly devices of low power, “elegant” convenient sizes. They will not survive in the industrial sector, as they are demanding on the mode of their operation – we work for about 15 minutes and rest for the same amount. Otherwise – overheating and …
Industrial angle grinders are workaholics. Such tools are able to work productively for a long time without interruption and overheating. In the case of grinders, these qualities of a professional tool are put on the scales and two other parameters: weight and cost. They are also increasing their importance in the “professional” category.
When choosing a tool, you should focus on the convenience of working with it and its effective capabilities in work. The price factor is also not an unimportant detail. Professional equipment breaks down, of course, less often, but its repair is more expensive.
We will understand the nuances of choosing a tool …
Signs of classification
Any electromechanical tool is characterized by many parameters, among which the power of the device never comes in last place. Let’s start with her!
The power of the grinder determines its interrelated parameters: capabilities (productivity), dimensions, mass. Existing angle grinder models fit in a power range from 0.5 kW to 2.7 kW.
Common “household” representatives of this tool are capable of developing from 800 to 1000 W of effective power, sufficient to perform most operations in the home. For long-term “industrial” or heavy domestic work (we cut concrete, brick, etc.), you should choose a grinder with a power of 1.5 kW or more.
But this parameter is an interconnected power, but not the main characteristic of angle grinders. The determining technological parameter is the maximum diameter of the installed disk.
Which diameter of the disc for the grinder is better: 115, 125, 150, 180 or 230 mm
For angle grinders, discs with a diameter of 115 mm to 230 mm are used. Practically capable of cutting only part of the disc, protruding beyond the body of the grinder.
Therefore, when choosing a 115 mm disc, you can cut through the thickness of the material no more than 25-30 mm. In the process of using the disk, this parameter decreases, since the disk wears out (erases), and given the number of revolutions and the performance of such units, this happens quite quickly – a couple of minutes and the disk “disappeared”.
When choosing a tool, it is necessary to initially analyze its future tasks and choose the right diameter of the disk:
- 115 mm – convenient for grinding, suitable for cutting only “small” parts. The tool for such disks has low power and, accordingly, is “convenient” to work with;
- 125 mm is a popular size. A grinder for such a disc is ideal for home use. And all varieties of grinding and cutting discs are maximally adapted precisely for this diameter;
- 150 mm – a certain middle between the 125th and 180th disk. You can take it for home, but for greater convenience, if you have financial capabilities, it is better to choose two separate tools;
- 180 mm – inconvenient for small jobs, optimal for construction and industrial use. Able to cut both a pipe and a brick;
- 230 mm – the maximum size of the “grinder” circle. Such a grinder will be ideal for large-scale construction work and ineffective in terms of ergonomics when performing small work.
In principle, by determining the required diameter of the disk, you should start choosing the grinder, and then “add” its power to the analysis. If a grinder of 600 W is suitable for one-time work in a circle of 125 mm, then for long-term work in the same circle it is advisable to choose a tool of 1-1.5 kW. A more powerful angle grinder will be less “tired” under load and, accordingly, the cycles of its operation will be longer, and the period of “life” longer.
Attention! In no case should you use larger discs on grinders designed to work with smaller discs. This will require unacceptable, from the point of view of TB and common sense, removal of the protective casing of the grinder, and the imbalance and inconsistency of the parameters can lead to inadequate “actions” of the tool when the disk is jammed.
The following types of disks are used in working with angle grinders:
- cutting metal;
- cutting stone;
- stone for dry work;
- stone for wet cutting;
- combined diamond wheel for cutting tiles;
- blade type discs;
- mandrel for wheels with Velcro;
- metal wire brush for cleaning the disk or cup form factor.
An important point to choose! If you are planning a “dusty” job involving cutting stone, brick, plaster, worry about the presence of a dust protection tool in your chosen model for such work. An unprotected Bulgarian will not last long in a dusty environment.
The number of revolutions of the spindle grinder
When choosing a grinder, you are unlikely to pay attention to the number of revolutions of its spindle. This, of course, is an important parameter in the operation of the tool, but it has already been optimized by the manufacturer for a specific model of grinder.
Interesting from a practical point of view is the ability to smoothly adjust the speed. This function can have powerful grinders, but more on that below.
For general information: the rotational speed of the disc of the grinder is in the range from 2800 rpm to 6600 rpm. Some models of grinders for discs up to 125 mm have a speed of up to 11000 rpm.
Ergonomics and safety
Since the grinder is still a manual tool, its ease of use is determined by the “organs” of interaction with a person.
Easy handling and reliable protection
For convenient operation and reliable holding of the tool in the hands, the grinder should be equipped with practical handles. Their well-thought-out options also play an anti-vibration role.
The provided options for right-handed and left-handed installation of handles will allow equally convenient operation of the instrument for “left-handed people” and traditional “right-handed people”.
When choosing a grinder, you must also take into account its mass. The angle grinder with a power of 0.6-0.8 kW weighs about 1.4-2 kg and usually has one handle. Such a tool is best suited for grinding. “Kilowatt” of power of the grinder will create a load on the hands of 1.9-2.3 kg. And the “giants” of 2-3 kW will not have less than 3.5 kg.
The presence of a protective casing on the grinder is required! Without it, you will play Russian roulette with your life. The fact is that the discs for the grinder are quite thin, but they rotate at great speed. A poor-quality disk or its defect can lead to rupture and scattering of fragments, which will inevitably lead to injuries. Therefore, the presence of a casing is not discussed.
When working on stone, brick or plaster, it makes sense to purchase a casing that allows you to connect a vacuum cleaner hose to yourself. Such casings are suitable for 230 mm discs and may also have a guide ruler for uniform cutting of grooves.
Change discs on the grinder
The ease of maintenance of the tool determines the additional time spent on “recharging” – changing the disk. In this, a spindle lock device is provided for this. By pressing the stop button, the driven gear is locked, and the nut is unscrewed with a wrench.
There are options for clamping nuts that allow you to work with yourself without a key. Such a composite nut is clamped by hand, and when the lower part of the nut stops on the surface of the disk, it is retracted by rotation of the upper part by hand. Such systems are especially relevant for frequent changes of disks on the instrument.
The nut of a standard grinder works for self-tightening, which leads to more difficult loosening than tightening.
Functional and protective automation
Convenience and safety of working with the tool contribute to additional functional “bells and whistles” of the tool.
A grinder equipped with a soft start system suffers less from short-term critical overloads at the time of launch. It is especially important to equip a similar system of powerful grinders with a significant mass of parts and the disc itself. Then, when turned on, the angle grinder gains momentum smoothly, does not twitch in the hands, and the motor windings and brushes do not experience strong surges in current.
The Bulgarian engine speed control system allows you to choose the spindle speed for any task: cutting, grinding, grinding, etc. These are additional amenities designed to optimize tool operating modes.
The system of stabilization of the spindle speed when changing the load on the disk greatly facilitates the processing of massive labor-intensive parts.
Disk wedge protection
Jamming of the disc in the material slot is a very dangerous phenomenon, especially for powerful grinders. The tool will simply escape from its hands with unpredictable consequences. To avoid this, a professional tool is equipped with a protection system against jamming of the cutting disc. In the case of a “wedge”, the instrument simply instantly de-energizes.
If the power supply to the tool was stopped at the time of its operation (someone, for example, pulled the plug out of the socket), then when the power is restored, the grinder can be protected by a safety system from spontaneous secondary start-up.
The branded tool can be equipped with a safety system for disconnecting the motor brushes when the supply voltage is lost. Re-inclusion of the rotating collector of a powerful engine threatens to burn the contact group. A brush shut-off system may also be provided for significant wear.
In the process of working with powerful grinders, the disk is generated unevenly, and certain vibrations of the tool arise, which do not positively affect the quality of work. To eliminate them, well-known tool manufacturers use a balancing system designed to dampen these vibrations.
Not all angle grinders have reliable protection against dust, which determines their unsuitability for cutting stone, brick or plaster. When choosing a tool, it is necessary to clarify this point if it is necessary to carry out “dusty” work.
A cordless tool is useful in two cases:
- in the absence of the ability to connect to the network;
- to eliminate the inconvenience of “transportation” for the network wire tool (for example, during high-altitude work).
Cordless grinders are classified in the same way as network options. Another parameter is added to their parameters – the time of continuous operation from one set of batteries. And this is a huge minus for them – a short battery life. An increase in its capacity will lead to an unjustified increase in the mass and cost of the tool.
Therefore, you should choose a battery angle grinder in cases of urgent need or in the presence of a sufficient number of replaceable batteries.
An alternative to using a cordless grinder can be the use of a diesel or gasoline portable electric generator of the appropriate power (consider the significant inrush currents of the grinder) to connect a power tool to it.
AND THE GRINDERS ARE NAMED PANASONIC
The pneumatic angle grinder is able to work for a long time without overheating in severe load conditions. They received the greatest distribution in the metalworking industry, but can also be used in the repair and construction and other fields of activity.
Its distinctive feature is the lack of an electric network cable and the possibility of complete isolation from the compressor or the air line. This tool can be used safely in high humidity conditions. Pneumatic grinders also have a higher spindle speed.
A gasoline carver is, of course, not a grinder and it is not intended for home use. But this professional tool allows you to perform some similar operations for the separation of solid materials, capable of long battery life, has a sufficiently large power.
A few points to make the right choice.
All the parameters of the tool listed above may have helped you navigate the functional equipment of the grinders, but did not bring clarity and specificity to the selection process. All grinders are initially similar, and you will be able to evaluate the correctness of the choice only during the long-term operation of the tool. But, nevertheless, let’s try to concretize the selection algorithm:
- We determine the required diameter of the disk – 125 mm is best suited for a house.
- Based on the operating mode, we determine the power.
- Determined by the need and the presence of additional functions.
- We are looking for models, trusted brands – in fact, everything matched to you will suit you, but …
- We look at the convenience of their body and the location of the handles.
- We get acquainted with the conditions and duration of the warranty.
Which Bulgarian is better: Makita, Bosch, Hitachi, Metabo or Devolt
It is definitely impossible to determine from the whole assortment which is the best grinder. This choice is individual and each model of a quality tool has its advantages and disadvantages. Considering the range of leading manufacturers Makita, Bosch, Hitachi, Metabo or Devolt, we can say that there is plenty to choose from.
Full “stuffing” will require significant investment in the instrument. Cost optimization is possible by selecting the optimal combination of functions in different models and rejecting those that are not so important for you in the household use of the tool.
Popular Hitachi with its always thought-out “graceful”, but convenient appearance pleasing to the eye and create additional comfort in work. 125-mm models have a rotation speed of up to 10,000 rpm with a power consumption of 650-800 W and a weight of up to 1.6 kg.
A grinder for a 230-mm disk will already “take” 2,000 W from the network, providing 6,600 rpm of idling. Its mass is 4.3 kg.
Let’s dwell on the 125 mm Makita. Here, the power range of popular models is in the range of 710-1400 W with a tool weight of 1.4 kg to 1.8 kg. They are designed for long-term intensive operation, they have a significant power reserve, stabilization of the number of revolutions, a system for limiting inrush current and other useful innovations. The Heavyweight on Makita’s 230th wheels will provide 6,600 rpm with a power of 2.6 kW. The mass of such a angle grinder is more than 5 kg.
Virtually all Metabo models are equipped with soft start systems, many are “able” to change the working disk without a key and smoothly control the speed.
Bosch is bewildered by the presence of a wide variety in the range of angle grinders. But you will not be mistaken, choosing this brand, you will simply be determined for a long time with the choice of a specific model.
American “yellow” Dewalt offers a number of reliable production models without unnecessary “bells and whistles” that will satisfy the most demanding consumer.
It’s clear that it’s better to buy a grinder from Makita, Bosch, Hitachi, Metabo or Devolt, we have no moral right. You will have to invest part of your time in selecting the right tool for you! To save your time, you can rely on the choice of a sales assistant from a trusted store, having previously acquainted him with the tasks planned for this grinder.
Note! All angle grinders are an instrument of increased mechanical danger and require careful and careful handling of themselves. Observance of safety measures during the work with the grinder is your life and health. And the non-use of goggles or masks is a tremendous stupidity and frivolity, the price of which can be quite high.