By virtue of a variety of interchangeable wheels or disks, this tool grinds stone, cuts rebar, routs mortar, sands woods, sharpens knives . . . nay, an Angle Grinder is not a Jack of All; it is a ‘Master of Many.’
What Is An Angle Grinder?
An angle grinder is a very versatile power tool that is a ‘grinder,’ and a dozen tools more. It comprises of a powerful motor, a handle, and a spindle or arbor plus one of many kinds of interchangeable wheels or disks. Most hobbyist and even semi-pro angle grinders operate on electricity. Compressed air is another power source that is used by powerful pneumatic grinders. Newer rechargeable battery-powered cordless grinders are also available; these are relatively smaller and somewhat less powerful. Petrol-powered grinders are usually the most powerful and heavy-duty ones of the lot.
The size category of an angle grinder is identified by a number, which can be one of 115, 125, 150, 180, and 230. These represent the diameter in millimetres of the disk that the grinder accepts.
An angle grinder’s motor rotates at much higher speeds than those of other power tools, typically at up to 10,000 RPMs at no load. It has a power output from 800 to 1,000 watts. Larger grinders have more power which can go up to 2,500 watts but they have slower speeds, typically 6,000 to 7,000 RPMs. Angle grinder speeds in RPMs specify maximum no-load speeds.
What are some different types of grinding wheels?
The key to the angle grinder’s versatility is the interchangeable disk, and it is the particular disk or wheel that ‘morphs’ the so-called grinder into a particular tool. Steel and stone can be cut with a cutting disk. Mortar can be ground out with a tuck-pointing wheel. Encrusted cement and rust can be loosened away with a wire cup. Dull edges of cutting instruments can be sharpened with a grinding wheel. Metal surfaces can be deburred with a flap disk.
Surfaces can be buffed and polished with a stripping wheel. And this is only a start! There are other kinds of disks, including variations of disks, and myriads of uses for them.
Angle grinders of one kind or another are practically standard equipment for wood and metal workshops, metal fabrication shops, auto mechanics’ garages, masonry outfits, construction sites, fire brigade stations, and rescue team kits.
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Makita’s top-class cordless kit is a perfect coming-together of form, function, features, and technology to the extent that its high price is wholly justified.
Makita’s (relatively) new, 2018-model angle grinder is an 18 Volt rechargeable battery-powered cordless kit that weighs a light 2.4 kilogrammes. It has a wheel diameter of 125 millimetres and a top speed of 8,500 RPMs. Cordless technology not only means there is no cable to get in the way, but it also introduces portability and flexibility.
This Makita features ‘cutting-edge’ technology including a brushless motor with soft start.
It has a very useful three-step battery charge gauge.
Often angle grinders sustain damage or simply die when they are overloaded; to avert such a possibility, Makita has equipped this rig with a nifty overload protection system. If the grinder is repeatedly overloaded, the current will be broken and the grinder will lock.
Another advanced feature is that the speed is increased or decreased automatically according to the load.
The design and shape of the handle make it unwieldy and this area could use some improvement. Gripe over, the technology, design, and features combine to make this kit a best-of-breed product. It is also less noisy than most corded models.
The package includes the obligatory auxiliary side handle and one grinding wheel.
There is no gainsaying the fact that this is a very expensive angle grinder, costing four to five times as much as most of the other selections in this set of reviews. Even so, this top-class power tool is yet another feather in Makita’s (already well-crested) cap.
It comes with a one-year warranty, extendable by two more years if the product is registered within 30 days of purchase.
This one’s not only for Makita fanboys, but also for any DIYer who values quality and technology and does not mind ponying up the extra pounds.
- The overload protection cut-off system is brilliant as it can save the angle grinder from being ruined.
- Going cordless brings portability and flexibility – use it up on the roof or outside your gate.
- The whole sweet package of dovetailing form and function, technology and design.
- Very expensive; will burn a hole in your pocket!
- The design and shape of the handle are not satisfactory.
Notwithstanding VonHaus’s kit inability to sustain heavy usage or loads, it is so effective, rich in features, and generously-outfitted that it is our Value Pick.
VonHaus’s angle grinder weighs 3.8 kilogrammes and boasts 900 watts of power. It can turn its 125-millimetre wheels at up to 12,000 RPMs. This economically-priced angle grinder is the bigger sibling of the maker’s 750-watt 115-millimetre kit that has a speed of up to 11,000 RPMs.
This rig is as powerful as its 900 watts suggests, and more. The accidental restart-prevention switch counts as a welcome safety feature.
Changing the wheel is quite a chore as the lock button has to be held down and the nut has to be engaged with a spanner. If your angle grinder usage requires frequent changes of disk, the complicated procedure can become a nuisance.
This angle grinder can begin to spark, crackle, or start to smoke, and can die under anything over continuous usage and heavy load; we feel that the high speed is a contributing factor. If you watch your usage and keep the load within bounds, it is very effective and does a brilliant job.
The auxiliary handle can be set in any of three positions – left, right, and top (vertically).
Available at a budget price, this angle grinder comes with a diamond-tipped cutting disk, two metal cutting disks, two grinding disks, and two flap disks, plus a pair of carbon brushes, grinding wheel cover and wrench, with a durable BMC case on top of it all.
A 125-millimetre angle grinder with a wattage of 900 and a complement of disks for only a fiver more than the lowest-priced 115-millimetre grinder in this set of reviews represents unbeatable value. An excellent choice as a beginner’s first angle grinder as the newbie need purchase nothing more than VonHaus’s package deal.
VonHaus provides a two-year warranty.
- A very powerful grinder that, when ‘on,’ does an excellent job.
- The very useful accidental restart-prevention feature is a bonus in a budget kit.
- The angle grinder, set of seven disks, and more is simply unmatched value for money.
- Under heavy loads or prolonged usage, the grinder will spark or smoke, or even die.
- The procedure to change the wheel is a real chore and it can become irritating.
Projecting and having raw power, this DeWalt’s other claims to fame are robustness and durability hitched to heavy-duty performance at a fair price.
DeWalt’s 3.61 kilogrammed 115-millimetre angle grinder is a ripper at 1010 Watts of power, and it is power you can feel. Within the class of 115-millimetre angle grinders, this one is Mr. Heavy Duty. Curiously, Mr. Heavy Duty is equipped with a soft start motor to make it two wins.
As a safety feature, a release switch when set in locked position prevents the angle grinder from inadvertent start-up, requiring a reset before it will start up.
DeWalt’s new guard design to improve fitment and removal without tools lives up to its billing, for the guard is truly quick and easy to adjust.
Even though it is so powerful, this angle grinder is relatively low in vibrations.
Some units are packaged with an Allen key instead of a two-pronged key, leaving you unable to change the disk!
This angle grinder is robust and durable and of very good build quality.
The expected auxiliary handle is included and the electric cable at 4 metres is longer than average. Comes with a rugged hard case. At its price point, we feel that a wheel or two should be included to allow beginners to get started.
A no-frills yet no-fuss mid-priced tool for the pragmatic types whose focus is on power and sturdiness.
DeWalt provides a one-year warranty.
- A very powerful and heavy-duty angle grinder.
- Particularly robust and durable, and of very good build quality.
- The guard design is one of the best, making fitting and adjusting it totally hassle-free.
- Some units ship with the wrong type of key meaning that you cannot change the disk
- Other than a case, no accessories at all – at the price, a wheel or two would be in order.
One doesn’t think of Wolf as a leading brand but on the evidence here one should: this cracking rig is super-tough and rugged and hard-wearing, and . . .
Wolf’s 850-watt angle grinder takes 115-millimetre disks. It has a speed of up to 11,000 RPMs.
This baby lives for its wheels: removing and placing disks is a snap, and it has an unusually good spindle lock.
It has very good build quality except for the on/off switch which is sub-standard in materials and design. It does not have a dead man’s switch.
This Wolf kit’s forte is not design or features or such; rather, it is an unusually tough, hard-working, hard-wearing angle grinder that takes everything you throw at it. An excellent product from an often-overlooked maker.
It comes with the obligatory auxiliary handle which can be attached on either side of the kit.
To get you started, one diamond-tipped cutting disc is thrown in. (For about £10 more this same item is bundled with three more diamond-tipped cutting disks of different styles.)
Whoever wants an inexpensive angle grinder that is rough, tough, and hard-wearing would be well advised to plump for Wolf’s kit.
Wolf provides a two-year warranty.
- This admirable rig is durable and tough and takes everything that is thrown at it.
- Very good design respecting removal and placement of disk.
- For such a well-made power tool, the price is a steal.
- The on/off switch is dodgy and does not look long-lasting.
- Does not have a dead man’s switch.
The usual Bosch quality in a robust kit of good build quality; if a bit wanting in toughness, its features, design, and price combine to provide value.
Tipping the scales at a mere 2.2 kilogrammes, Bosch’s pocket-friendly 115-millimetre kit delivers 11,000 RPMs and 700 watts of power.
Its dust protection system that prevents dust from accumulating in the ball bearing is an excellent feature that is meant to extend the life of the power tool; unfortunately, it is not a panacea.
The switch is sub-standard in materials and design and it is quite difficult to lock in the on position; therefore, though the switch is not truly a dead man’s switch, it tends to function as one.
Changing wheels is quick and easy; just press the spindle lock button, manoeuvre the spindle, and remove the wheel.
Bosch’s grinder is noisier than average and when one is using a grinding disk the vibrations can get uncomfortable.
This kit is clearly robust and has the build quality one has come to expect from Bosch. A great choice for moderate-heavy work but not for extended heavy usage under which conditions it can seize up and give up the ghost.
You get no accessories at the bargain-basement price other than the expected auxiliary side handle.
Bosch provides a two-year warranty, extendable by one more year if the product is registered within 28 days of purchase.
Bosch is the brand of choice for many in the British Isles and it shows because the PWS 700-115 is Amazon UK’s top-selling angle grinder.
- On the one hand, this kit is ultra-light; on the other, it speeds like the devil.
- Clearly robust and of good build quality.
- It is the UK’s top-selling angle grinder so Bosch must be doing something right.
- Under heavy usage or load, the grinder can seize up and die.
- It is noisier than average and also prone to vibrations when a grinding disk is being used.
How To Use An Angle Grinder
Using an angle grinder is, in effect, using a different power tool depending on the type of wheel and the task at hand. Therefore, there is no one way to use an angle grinder – it depends on the task. First, you have to select the right type of wheel for the job. Fit the wheel on to the arbor or spindle with a washer and nut except when using a wire disk or cup which are screwed in place of the arbor itself. As a general rule of thumb, if you are not working on a structure or structural element and the job is not one of loosening, scouring, buffing, etc., then hobbyists and DIYers ought to secure the workpiece with clamps or a vice. The rest very much depends on the particular type of job.
For example, if you plan to scour accumulated, caked dirt on a shovel, the job can be tackled casually. You could keep the shovel firmly in place by keeping one foot on it as you crouch. The disk would be applied laterally to the shovel’s blade so that most of the wire cup’s surface stays in contact with the area to be cleaned. But if you intend to cut metal, the process could not be more different. The grinder must be controlled with a firm grip and the edge of the cutting wheel must be kept perpendicular to the workpiece.
If the job requires any type of grinding, sanding, deburring, blending, etc., apart from the choice of wheel you also have to make a choice of wheel type, either 27 or 29. A Type 27 wheel has a straight, flat edge whereas a Type 29 wheel has an angled edge, i.e. the wheel appears to be a flattened cone when viewed edge-on. For example, for smoothing and finishing flat surfaces a Type 27 is the wheel of choice; for deburring and rounding edges, a Type 29 wheel is called for.
No matter what the type of the wheel, another variable is the thickness of the wheel. Although cut-off wheels are much thinner than grinding-type disks, for each type of wheel you can choose from different thicknesses. The thinner a cut-off wheel, the more efficient it is but it is also more prone to shattering.
Finally, you have to choose the right speed for the task at hand and as suits the wheel in question and also the circumstances you are working under. If you are working in a proper workplace, if the workpiece is secured, if you are wearing safety gear, if a relatively thicker disk will be used, and no inflammable materials are nearby, you can use high speeds and do a quicker, better job. On the other hand, the more conditions that are not met, the slower the speed that you are obliged to use.
Depending on the job, an angle grinder produces flying debris, metal shards, mortar/stone particles, dust, or sparks. Sometimes the wheel itself can shatter with a jagged piece flying off at high velocity. If the wheel catches in a structural or fixed workpiece, the resulting jerk can loosen your grip on the grinder.
Cut-off wheels are particularly dangerous. For one thing, they are very thin and for another, they are usually attacking hard materials. Imperfect handling of the angle grinder for any reason, for even a split second, changes the contact pattern between the wheel and the workpiece, causing lateral forces to increase; in turn, these can cause the wheel to shatter.
Because of the facts outlined above, it is critical to observe a few safety rules:
- Wear full face and neck protection and gloves, and even more so when using cutting disks.
- Whenever possible secure the workpiece with clamps or in a vice.
- Whenever you will not be using the full surface of the disk, attach (one of) the wheel guard(s).
- If you are using a cutting wheel, the spin of the wheel should be away from you and not towards you
- If you are using any type of abrasive wheel near an edge, the spin of the wheel should be away from the edge and not into it.
- Do not ever use any type of cutting disk for a purpose any other than to cut the kinds of material that that particular disk is meant to cut.
- Unplug the tool before changing wheels.
- Do not allow anyone to come near while you are operating the angle grinder.
- Position the grinder and workpiece or structure so that debris falls or flies away from you.