One the most versatile tools to have in the home workshop is the angle grinder. Angle grinders are used to cut, grind and polish metal, as well as to cut and grind masonry. Although one does not immediately associate angle grinders with woodworking, they can also be used very effectively to sand down and shape wood.
Of course as with any popular power tool, there are a number of makes and models available on the market each with its own features and unique characteristics, often making it a challenge for the average DIY-er to choose the best angle grinder for their workshop and one that perfectly suits their needs. So here at DIY fidelity, we are going to examine the humble angle grinder in all of its glory, looking at the different types available and the different features that various brands and models offer, in an effort to make your angle grinder buying decision an easier process.
Types and General Characteristics of Angle Grinders
Angle grinders are usually referred to by the size of the cutting or grinding wheel that they accept. They come in a range of sizes to accommodate the variety of metal-working and stone-shaping jobs one finds in a typical workshop or on a job site. The most common angle grinder sizes range from 4.5 inch machines up to 9 inch behemoths, and although there are both smaller and bigger angle grinder-esque machines available, they are less commonly classed within the angle grinding category. Angle grinder sizes may be represented either in imperial or in metric units. The common sizes include:
4.5 inch angle grinder: The most popular angle grinder in workshops of today is the 4.5 inch machine which has the characteristics to satisfy the requirements of most DIY-ers and work professionals while not being overly expensive.
Spindle size: The commonly used angle grinders, from the 4.5 inch angle grinder up to the 9 inch angle grinder all possess the same size spindle namely, 22.2 mm in diameter or an M14 thread. This near universal spindle size makes life easier when buying cutting and grinding wheels, however, extreme care should be taken not to use wheels that are designed for one size of angle grinder in another size machine due to the different rotational speed specifications.
Mains vs battery-powered: Angle grinders also come in both mains electricity-operated as well as battery-operated formats. Although battery-operated power tools have their obvious advantages, due to the rotational speeds and power required for most jobs with angle grinders, corded mains-operated angle grinders tend to be the favoured type in the workshop, while battery-operated angle grinders are more useful for smaller less demanding cutting and grinding jobs.
Types of Angle Grinder Discs
As angle grinders can be used in a variety of different cutting and grinding jobs, there is naturally a wide range of different cutting and grinding wheels available each ideally suited to cutting, grinding or polishing a specific material. Discs and wheels for angle grinders are usually labelled with the material they should be used on, which includes:
Disc thickness: In general, discs made for grinding and polishing will be relatively thick in order to withstand the pressures experienced on the flat surface of the disc, while cutting discs will be comparatively thinner and should never be used for grinding or polishing due to their greater fragility.
Direction of rotation: Some angle grinder wheels, particularly cutting discs, have a specific direction in which they should turn during operation, therefore they should only be installed on the angle grinder in a single orientation to ensure that they turn the correct way. These unidirectional discs will have their direction of rotation clearly marked on them, while those wheels that have no directional markings may be installed on the angle grinder either way round.
Threaded discs: Some angle grinder discs have a threaded spindle hole that allows them to be quickly installed on to an angle grinder by simply winding it on to the M14 thread that is typical of most angle grinder spindles. In such cases, using the wheel locking flange nut to secure the disc to the angle grinder is not always necessary as the disc will only wind on even more tightly as it spins in the angle grinder.
When it comes to angle grinders, safety is the number one priority above all else as this category of power tool can be more dangerous than most if used improperly or if the right safety precautions are not taken. Consequently we're going to dedicate a whole section here to looking at the safety aspects of using angle grinders.
The most important precaution to take when operating an angle grinder is to ensure that all the correct safety equipment is used to protect oneself in the event of an angle grinder wheel failure or other mishap. The following safety kit is essential and should be worn at all times whenever an angle grinder is in use:
Angle grinder wheel rotation speeds
In general, the smaller the angle grinder, the greater the speed at which its cutting or grinding wheel will spin. As the wheels themselves usually have a maximum rated speed at which they can be spun, a cutting or grinding wheel should never be used on a smaller angle grinder than it was designed for, otherwise one risks having the disc fail and disintegrate at the higher speeds of the smaller angle grinder causing a significant safety risk to the operator. Furthermore, some types of angle grinder wheels, namely metal cutting discs, tend to get smaller as they are used, and a common misconception is to use the worn-down discs in a smaller angle grinder once they get to a size that fits the smaller machine - this should never be done since the wheel is unlikely to have been rated for the higher speeds of the smaller grinder! Maximum rotational speeds are usually indicated on the angle grinder wheels themselves and these should be strictly adhered to at all times.
Safety guard removal
All angle grinders come fitted with an adjustable wheel guard that protects the operator's hands from accidentally touching the cutting or grinding wheel when in operation. The guard is also there to help prevent debris and sparks from coming towards the operator while the angle grinder is in use, and it also acts as a barrier in the event of the angle grinder disc breaking up. Consequently, removal of the protective guard from angle grinders should rarely, if ever, be done. There are some occasions when the guard has to be removed in order to perform the task at hand, such as when grinding on a flat surface using a flat wheel, however, on these occasions the type of angle grinding wheels used are inherently at a lower risk of breakage and therefore less of a safety hazard.
Cutting and grinding technique
A little bit of skill is required when using an angle grinder and there are a few things to remember when operating the tool:
Angle grinding wheel care
Care should be taken when handling and storing angle grinder discs to ensure that they do not become damaged, cracked or weakened and that they don't become a safety hazard when used on the angle grinder. Handling tips include:
Steel & stainless steel: When cutting and grinding metal, it is important to know which type of metal you are dealing with. Most angle grinder metal-specific discs are designed for the cutting and grinding of steel or, if they are labelled with 'INOX', stainless steel.
Aluminium: Since the wheels for cutting and grinding metal are usually made from aluminium oxide, they can not be used successfully to cut and grind aluminium. Instead, to cut and grind aluminium-based materials, masonry-specific cutting and grinding discs can be used, but in such cases, care has to be taken since the dust produced will be flammable and poses an explosive risk.
Copper & magnesium alloys: Cutting and grinding of some copper alloys can be detrimental to health as they can release toxic substances during the process, while the dust produced from machining magnesium-based alloys can pose a significant fire hazard.
Other safety tips
Which angle grinder should I buy?
So now we know the different types of angle grinder out there and the different types of jobs we can use an angle grinder for, how do we go about picking the right one for our workshop given all the different makes and models? One of the ways to make your angle grinder decision is to look at the different features and characteristics that each one offers. Below we go through each of the components that we find on today's modern angle grinders and their usefulness in the workshop.
Corded vs Cordless
Probably the first question to ask when deciding on a new angle grinder is whether it should be mains electricity-powered or battery-powered. The pros and cons of each type of power system is discussed in our general power tools page, most of which also apply when choosing an angle grinder. The primary factors affecting which type of angle grinder to go for include personal preference, how the tool will be primarily used, access to a universal power tool battery-charging system, and affordability.
In general, mains-powered angle grinders are higher power, unlimited in runtime, don't require battery discipline (i.e. keeping batteries sufficiently charged), and are less expensive. On the other hand, cordless angle grinders don't need to be close to a mains electrical socket to operate, and they are generally easier to work with, not having an electrical tether to contend with.
Brushed vs Brushless
If a cordless angle grinder is to be chosen, then one of the next options to think about is whether the angle grinder should have a traditional brushed electric motor or a more advanced brushless one. Brushed electric motors make use of small carbon brushes that facilitate the electrical connection to the moving parts of the motor. Brushless motor designs, in contrast, do away with these brushes giving angle grinders that make use of them several advantages over brushed ones:
Clearly, when it comes to deciding between brushed and brushless angle grinders, the latter type are always going to be superior to the former. Consequently, when it comes to cordless angle grinders, a brushless one is the recommended choice assuming its higher cost is within one's budget.
One of the key components of angle grinders is the wheel guard which protects the user from accidentally touching the spinning wheel and from any debris ejected off the workpiece towards him. This wheel guard, which only shields part of the angle grinder wheel, has to be regularly adjusted so that it is optimally positioned as the angle grinder is operated in different orientations. Consequently, the mechanism for adjusting the wheel guard is an important feature to take into account when choosing an angle grinder. Most budget angle grinders facilitate wheel guard adjustment via a screw that needs to be loosened and tightened using a screwdriver. This can make regularly adjusting the wheel guard a tedious task. As a consequence, those that plan to use an angle grinder more intensively, should opt for an angle grinder where the wheel guard can be instead adjusted through the use of a finger latch making it a much quicker and easier process.
Another important feature of angle grinders is the side handle which should always be made use of to ensure full control of the angle grinder during use. Almost all angle grinders have the facility to attach the side handle to either side of the angle grinder in order to accommodate both left-handed and right-handed users. Some angle grinders even have the ability to attach the handle in other positions (such as to the back of the machine) which can make the angle grinder even more comfortable to work with in certain situations.
In general, angle grinders favour one of two types of handle orientation. Some brands of angle grinders, such as DeWalt angle grinders, favour a side handle that is oriented exactly perpendicular to the body of the machine, whereas other brands such as Bosch or Makita angle grinders have handles that are tilted forward at an angle greater than 90° to the body of the tool. Which is better comes down mostly to personal preference, although some more experienced angle grinder users have sometimes suggested that having a side handle at 90° is more comfortable and less obstructive specifically when using the angle grinder for cutting.
Dead man's power switch
Most budget 4.5 inch angle grinders have a sliding power switch which can represent a safety hazard if the angle grinder is accidentally dropped while the power switch is locked in the 'on' position. In such cases, the power tool will keep running uncontrollably, presenting a significant safety risk to the operator and those around him. To counter this safety risk, some more expensive angle grinders will feature a dead man's switch that ensures that the power switch cannot physically be left in the 'on' position if the operator is not holding it down.
Restart (No-Volt) protection
Another risk arises, especially on older angle grinders, if power is suddenly lost to the machine while it is in operation. If power is then restored to the angle grinder, the tool will reactivate unexpectedly raising the safety risk to the operator. As a result of this safety hazard, more recent 4.5 inch angle grinders will have a restart protection feature, which prevents tool re-activation after a power failure without power switch cycling.
Some angle grinders have a feature known as 'soft start' which means that the angle grinder does not immediately reach full rotational speed when switched on but instead more slowly revs up to its maximum speed. This has the advantage of reducing the kickback that an operator experiences when first starting the power tool making it a little safer to use.
Angle grinder girth
The body thickness or girth of the angle grinder can also be an important factor to take into consideration when purchasing the power tool, as angle grinders with a larger girth can make holding onto them more challenging particularly if the operator has smaller hands. So as a general rule, the smaller the girth of the angle grinder, the less tiring it will be for the hands. This, in turn, will allow for longer operating times, an important consideration since most angle grinder cutting and grinding tasks require significant amounts of time to complete.
Popular CORDED 4.5 inch Angle Grinders in the UK
(If you are located in the US, then check out what the popular angle grinders are in the US here)
on both sides
|Einhell TC-AG 115|
|Einhell TE-AG 115|
|Bosch PWS 700-115|
|Bosch GWS 7-115|
|Black & Decker KG115|
on both sides
Popular CORDLESS Angle Grinders in the UK
-- Information not available
** weight includes battery pack - depends on size of battery installed
^^ X-LOCK system: A spindle lock is not needed as the disc attachment uses a unique tool-less method
So what is the best 4.5 inch angle grinder in the UK?
Einhell TE-AG 115/600 Angle Grinder Review
The German power tool company, Einhell, sells a range of angle grinders catering to the different needs of DIYers and professionals. One of their mains-powered machines is the Einhell TE-AG 115/600 angle grinder, which is one step above their most basic wired model, the TC-AG 115, sharing most of the features with the lower-end model, but with a couple of upgrades.
As with most Einhell tools, the Einhell TE-AG 115/600 angle grinder feels robust, having been constructed from decent-quality materials. Its 600W motor is more powerful than the basic TC-AG 115, but it is still slightly underpowered compared to other competing brands. The motor in this Einhell angle grinder also has a soft-start mechanism, which means that the power tool is less likely to 'jump' out of the operator's hands due to start-up forces, and the spindle turns at 12,000 rpm when up to speed. Like most angle grinders, it has a spindle lock which is activated through the push of a button on the head of the tool, allowing the blade to be changed with relative ease. The additional or side handle that typically accompanies angle grinders runs at 90° to the body of the tool when attached, and can be installed on either side of the machine catering to both left- and right-handed individuals. This handle can also be attached in a third rear position which gives the angle grinder even more versatility in its handling characteristics.
As with most of today's modern angle grinders, this Einhell angle grinder also incorporates restart protection preventing the power tool from powering up in the event the power switch is on when plugging in or after a power cut. The power switch itself also incorporates a safety mechanism whereby, in order to turn the power tool on, it has to be pushed to the right and then upwards in a relatively unnatural motion. This unnatural movement acts as a safety mechanism preventing unintended activation of the power tool, however, it can also be a little awkward and annoying for some regular operators of the tool. Like with most consumer angle grinders, one also has to be mindful of this lock-on style power switch which will not deactivate the power tool if the machine is accidentally dropped during operation. This could have been solved by the incorporation of a dead-man's switch that springs into the off position if the angle grinder leaves the hand inadvertently, but this was probably not incorporated to keep the overall cost of the tool down.
In addition to these standard features, the TE-AG 115/600 also has a few other capabilities. First and foremost is the tool-less adjustment mechanism for the wheel guard. As alluded to elsewhere, using and positioning the wheel guard is a critical safety feature of any angle grinder. So having a design that allows for tool-less blade guard adjustment means that the protective barrier can be quickly repositioned for optimal safety. The ease with which it can be adjusted makes it more likely that it will be used properly. This contrasts with an angle grinder that requires the use of a separate tool each time the wheel guard needs repositioning, which will make users less inclined to bother with the more tedious process, exposing them to a greater risk of injury.
One of the unique features of the Einhell TE-AG 115/600 angle grinder is the storage solution for the face spanner that is used for tightening and loosening the blade securing nut or flange on the angle grinder. The spanner, when not being used, has its home at the end of the side handle, which is an innovative way to reduce the chance of misplacing it. Other notable features on the power tool are the generous 3-metre length power cable and the incorporation of a cable clip at the base of the tool, which can be used to secure the coiled power cable during storage or transportation.
As for the cons with this Einhell angle grinder, the most significant negative is the fact that it does not come with any cutting or grinding discs included in the box, all of which have to be purchased separately. Similar to other DIYer-targeted power tools, another issue to be aware of is that the angle grinder will not fare well if overworked. This is because it is designed for more intermittent cutting and grinding needs, and not for the heavy user who is more likely to cause it to overheat. Power tools becoming overly hot during operation are more likely to suffer from motor burnout, which has happened to some users of this tool who appear to have over-worked it without giving it sufficient cool off time.
Overall, the Einhell TE-AG 115/600 machine is a good angle grinder for the occasional DIYer, being robust and with some well-designed features. It fits nicely into the range of power tools offered by the Einhell tool company, which is renowned for selling reliable tools at a reasonable price.
Bosch PWS 700-115 Angle Grinder Review
The PWS 700-115 angle grinder from Bosch is a low cost 4.5 inch power tool which is designed and built for the DIY enthusiast. As one might expect from a Bosch machine, its features are well thought out and its build quality excellent.
The Bosch PWS 700–115 has a 701W motor that outputs 11,000 RPM to the spinning wheel. At 1.7 kg, it is a relatively small and lightweight machine with a relatively thin girth which makes holding the angle grinder an easy prospect even for operators of lesser forearm strength or with smaller hands. The side handle on the Bosch machine can be fitted to either side of the angle grinder body so that both right-handed and left-handed individuals can use the tool comfortably. However, it should be noted that the side handle attaches at an oblique non-perpendicular angle which some angle grinder users might find awkward to hold especially when using the angle grinder as a cutting tool.
Safety-wise, the Bosch PWS 700–115 incorporates a high level of restart protection as standard which means that the machine cannot be inadvertently turned on without power switch cycling after power has been removed. The power cord itself is a good length and is relatively thick compared to other power tool cords. But possibly the most important feature of all on this Bosch angle grinder is the ability to adjust the blade guard without the use of any tools, something that is not always found on today's crop of modern angle grinders that are available to the consumer.
Dislikes with the Bosch PWS 700–115 angle grinder include a power switch which is a bit fiddly to lock on, sometimes inconveniently requiring the use of both hands. In addition, the PWS 700–115 is not designed for anyone who plans to do a lot of intense angle grinding or cutting (e.g. construction site workers), as the electric motor tends to become hot relatively quickly with heavy use which can lead to burn out if it is not given sufficient time to cool down. This disadvantage is particularly obvious if the Bosch PWS 700–115 is operated alongside a more professional tool that is designed to operate at a much higher level. Finally, one last niggling issue with the Bosch PWS 700–115 is not unique to the Bosch machine but typical of many 4.5 inch angle grinders, in that the spanner used to tighten the wheel is straight and flat which can sometimes make it difficult to attach and release thicker grinding or sanding wheels.
Overall, the Bosch PWS 700-115 is a good buy for the DIYer or the professional that uses it only sporadically and for short periods. It has a nice set of features and a good brand name power tool company behind it. However, anyone needing an angle grinder for more intensive work will likely be better served by going for an equivalent machine from Bosch’s blue range of professional tools.
Bosch GWS 7-115 Angle Grinder Review
The GWS 7-115 angle grinder from Bosch is a compact professional tool with a powerful 720 W motor. It's an impressive machine for lots of reasons, but some chief advantages are its compact design and small handle profile. As a result, you'll be able to use this angle grinder for more extended work sessions than you otherwise would since your hand will not become tired even with the constant vibration from the tool.
The GWS 7-115 is constructed with special air inlets near the front of the motor which allow cool air into the enclosing chamber and ensure that the motor doesn't become too hot as you use it. This both benefits the tool in the short term, since it makes it resistant to overheating and failure, and in the long run, as the motor won't degrade quite as dramatically over time.
The angle grinder is also equipped with restart protection which will keep yourself and others safe and prevent it from being accidentally turned on. But that's not all the tool has to offer when it comes to safety. It's also equipped with an extra-tough anti-rotation protective guard on the back of the grinder blade. This protects your fingers both from the blade itself and from potential chips flying off the material you're grinding. The only downside with the guard is that it is not tool-less to adjust requiring the use of a Allen key to lock and unlock it.
The flat gear head and compact design of the tool are excellent for working in tight conditions and narrow spaces. The only downside to its design is the corded nature of the machine; while this provides a steady power supply to the motor, it does hamper your manoeuvrability to some extent. A cordless angle grinder would allow you to go anywhere you pleased. This isn't a huge flaw, but it's at odds with the otherwise nimble design of the handle and gear head. The cable isn't even particularly high quality; it's made of a low-quality plastic that might kink or break over time. You'll probably want to check on it now and again to ensure there's no danger of electrical damage to you or the tool.
This lower cable quality seems to be echoed with some of the previous users of the tool. A few users report that the device breaks down after about the six-month mark. While it's impossible to know the exact reasons for these malfunctions, it's likely that the tool simply isn't made with materials durable enough to withstand consistent heavy use past half a year or so.
Yet other users continue to describe its benefits. The small size of the grip – only 56 mm in diameter – makes it among the easiest angle grinders to use of its class on the market. It's also worth noting that it's relatively simple to control, with a single on and off switch rather than a variable speed setting. This will be either a positive or a negative depending on your needs, though it's not surprising to find a lack of variable speed choices with a tool of this size.
It also doesn't need any extra tools to lock the spindle, which itself happens to incorporate an M14 thread. So with the right discs, you can quickly switch out your grinding blade with your hands alone too and make it easy to change Bosch angle grinder blades in the middle of a workday. Overall, the GWS 7-115 is easy to maintain and even has motor brushes that are easily replaceable via a bespoke access door.
Additionally, you have a little extra customisation in that you can mount the side handle on either side of the main grip. This handle is positioned at more than 90° relative to your body in most cases, so it's optimally placed for keeping your grinding steady and smooth, although some older hands may not like it.
There aren't any additional accessories included with the purchase, but that is not surprising given the low asking price. Most would probably appreciate at least a cutting or grinding wheel to be part of the package, but you'll have to make do with sourcing your own supply of discs.
All in all, the GWS 7-115 is a decent piece of hardware and a reliable angle grinder, at least when not overused. It's notable because it's affordable and easy to use, and it's one of the most compact and most manoeuvrable grinders on the market so long as you can handle the cable.
DeWalt DWE4206 Angle Grinder Review
The DeWalt DWE4206 is our current favourite in the 4.5 inch angle grinder category, exhibiting a range of features as well as robustness, and all for a non-bank-breaking price.
The DWE4206 angle grinder incorporates a very powerful 1010W electric motor capable of taking on almost any cutting or grinding job. It also features tool-free wheel guard adjustment using a finger latch system, and a unique DeWalt-designed dust ejection system that minimises dust and debris ingress into the body of the tool that houses the motor (see video below). The DeWalt machine's body also sports a small girth or thickness, making holding and handling the angle grinder a comfortable experience.
In terms of safety, the DWE4206 has most of the essential safety features you would want in an angle grinder. These include a safety switch and restart protection to ensure that the power tool cannot be inadvertently activated even after a temporary power failure. It also incorporates the soft-start feature which reduces the kickback from the power tool on startup.
All in all, the DeWalt DWE4206 angle grinder is worth getting if you're planning to do a serious bit of metal or stone cutting or grinding, or you are planning to use an angle grinder on a frequent basis, as you will be thanking yourself later for that extra bit of quality in getting the job done.
Makita GA4530R Angle Grinder Review
The Makita GA4530R (GA4530RKD) angle grinder is one of a series of angle grinders that the Makita Corporation makes for the consumer market. It is sold in the UK from a number of retail outlets (such as Amazon) and is also marketed by Makita in other places around the world. In the UK, you can also pick up this Makita angle grinder under the model number GA4530RKD which is essentially the same angle grinder but with a plastic carry case and an extra diamond disc included as part of the package. Consequently, in this review of the GA4530R, we will sometimes refer to this Makita angle grinder as the GA4530RKD especially when talking about its carry case.
The GA4530R angle grinder has a power rating of 720W and rotates its spindle at 11,000RPM. The unit does not have the ability to vary its rotational speed but it does have a soft-start functionality which gives the angle grinder a safer start-up. As with almost all angle grinders these days, the Makita GA4530R also incorporates an anti-restart safety function which prevents the angle grinder from turning on unexpectedly if the power switch happens to be set to the on-position when electrical power is applied.
Design-wise, like the majority of angle grinders available today, the GA4530R angle grinder comes with a side handle that is angled 110° relative to the body of the power tool. It also has a lock-on switch so that the power switch does not have to be continually depressed for the power tool to run making it more comfortable to use for long periods. For robustness, the GA4530R has been designed to a high standard which is something that is not uncommon for power tools from Makita - a Japanese company that prides itself on precision engineering and tools that last. For example, the seals that protect the motor and bearings from dust and debris have a labyrinth design to prevent particulate ingress. Another feature of the angle grinder emphasising quality is the precision-machined bevel gears that impart upon the Makita GA4530R a service lifespan that is touted to be twice as long as more generically-manufactured angle grinders of less reputable brands.
On the more negative side, the GA4530R angle grinder does come with a couple of features that are lacking, which make it less convenient to use than even some cheaper generic-type angle grinders. The foremost inconvenience is the need to use a screwdriver in order to adjust and secure the blade guard. This can make ensuring the blade guard is in the proper position to protect the operator's hands a tedious process especially when the cutting or grinding angle of the angle grinder needs to be changed frequently. This also makes the Makita angle grinder slightly less safe to use if the operator is not religious in his or her handling of the tool.
Another minor dislike with the Makita GA4530R when it comes as the model number GA4530RKD is with its carry case. Unfortunately, here Makita has skimped a bit on design with the carry case not fully in keeping with what one usually gets from the Japanese company. Although the case is made from robust plastic, the internal design of it makes it more difficult than necessary to fit the Makita angle grinder and its electrical cable inside. In addition, the design of the clasps that keep the case closed are not particularly awe-inspiring with better locking mechanisms observed on power tool cases from other brands and even from Makita itself.
In summary then, as with most Makita tools, the GA4530R angle grinder is a high precision, high-quality tool that is generally more costly than other angle grinders on the market. However, the higher cost is likely justified by the better performance and the longer life that one will likely see from the GA4530R and which is typical of power tools from Makita. The GA4530R does lack a feature or two that are now commonly seen on angle grinders from other brands but they are not absolutely essential and one can usually do without them especially if the angle grinder is only being used for sporadic DIY jobs.