What Is the Best 4.5 Inch Angle Grinder
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Photo: Tom Scalisi
Angle grinders are versatile power tools that can handle a variety of projects, such as cutting iron pipe to replace a faulty valve, carving wood to craft furniture, cutting tile for a backsplash, and removing grout from between tiles. Interchangeable rotating discs—some made for cutting and others with an abrasive edge for grinding—can be swapped out based on the application. For safety, a guard sits between the disc and the handle to protect the operator. If you're ready to add an angle grinder to your tool collection, read on to learn more about the tool's capabilities during our testing and what to look for in an ideal model.
- BEST OVERALL: Makita XAG04Z 18-Volt 5-Inch Angle Grinder
- BEST BANG FOR THE BUCK: Metabo HPT 4.5-in 6.2-Amp Angle Grinder
- UPGRADE PICK: DEWALT 20V MAX XR Brushless Cut Off/Grinder
- BEST CORDLESS: KIMO 20V Cordless Angle Grinder
- BEST CORDED: PORTER-CABLE Angle Grinder Tool, 4-1/2-Inch (PC750AG)
- BEST LIGHT-DUTY: BLACK+DECKER Angle Grinder Tool, 4-1/2-Inch (BDEG400)
- BEST HEAVY-DUTY: DEWALT Angle Grinder Tool, 4-1/2-Inch (DWE402)
Photo: Tom Scalisi
What to Consider When Buying an Angle Grinder
There are a few things to understand before clicking "add to cart" on just any old angle grinder. The best angle grinders may have unique features, different power sources, and some might simply be better suited to particulars. The following points are worth considering when shopping for the best angle grinder.
Disc Size
Angle grinders come in sizes, denoted by a number that refers to the maximum diameter of the grinding wheel or disc it will handle. For most DIY projects, a 4-, 4.5-, or 5-inch disc will suffice. In fact, these compact sizes and weights are ideal for DIYers, as larger discs can become unwieldy or tedious to work with.
Larger discs (up to 9 inches) are more commonly used in industrial situations by professionals cutting through thick pieces of material. As the disc gets larger, the grinder itself must be larger to handle the cutting strength. This translates to a heavier tool that's likely to cause hand fatigue sooner than using a smaller angle grinder.
Power Source
Angle grinders are available as corded models (which plug into an electrical outlet) and cordless (which use a battery).
- Corded grinders typically generate more power at a consistent level due to the direct connection to the outlet. But corded models restrict the user to a physical location, limiting range without an extension cord. The cords can also be a tripping hazard and, therefore, a nuisance while working on a project.
- Typically, cordless grinders lack the sheer power of their corded counterparts. And functionality depends on battery capacity, so a dead battery could mean downtime in the middle of the project. On the plus side, cordless angle grinders offer hassle-free mobility and are better for use in tight spaces.
Speed
Angle grinder speed is measured in revolutions per minute (rpm). Speeds typically range between 5,000 and 10,000 rpm, though some very robust grinders reach up to 12,000 rpm. Keep in mind, however, that the rpm rating is under "no-load" conditions, meaning that the disc isn't cutting or grinding anything, just spinning in the air. Once the disc is cutting or grinding, that speed will lower considerably.
Obviously, the higher the rpm, the easier and more quickly the tool can cut through the target material. But the disc also becomes hotter at higher speeds and could be vulnerable to rupture—an injury risk. Be sure to use the correct disc for the task, and note the maximum supported speed marked on the disc. For example, a disc rated at 7,500 rpm that is running faster can break under the force, sending shards of the grinder wheel flying.
Voltage/Amperage
Angle grinders measure power output potential in volts (V) and amperes (amps). Cordless angle grinders use volts to measure the power available from their battery, with most cordless models using 18-volt or 20-volt batteries and outliers ranging from 7.5 volts to 24 volts. The "magic number" in most cordless power tools is 18 volts to 20 volts, offering the best mix of affordability and functionality.
Voltage readings on corded angle grinders only indicate whether they can be used with 120-volt or 220-volt power outlets. Shoppers can assess the power output potential of corded models by checking amperage, which ranges from 5 amps to 15 amps. Larger discs will require a larger output, so for a 7- or 9-inch grinder, expect it to have a higher power output potential.
Hand Guard
The guard on an angle grinder is a crucial safety measure that covers half the disc. Its purpose is to protect the user's hands, by preventing sparks and debris from flying toward the user, and to protect surfaces from damage when using the grinder in tight spaces.
Some angle grinders have a movable guard, and others have a fixed guard. The movable option is more popular as it allows for left-handed or right-handed use and can adjust to better protect the user from flying debris. If left untightened, however, a movable guard can fall off the unit. Fixed guards are more robust, and there's no risk of them coming off a grinder.
Soft Start
Because angle grinders are fast, powerful tools, they can recoil a bit upon power-up. This is particularly true if the grinding wheel is large and heavy. The recoil from the motor can result in the angle grinder jumping in the user's hands, potentially causing serious injury.
To combat recoil, soft-start technology reduces the power output to the motor at first, slowly increasing until the angle grinder is fully up to speed. This throttled control over the power output prevents an angle grinder from recoiling during start-up, increasing safety while also reducing the jolt to the user's arms and wrists.
Tips for Buying and Using an Angle Grinder
Keep these tips in mind when choosing and using an angle grinder.
- The most common DIY projects where an angle grinder will be of use—such as cutting tile or pipe, metalworking, or removing grout and mortar—rarely require more than a 4.5-inch grinder.
- The ongoing vibration of an angle grinder can cause what is known as Hand-Arm Vibration Syndrome (HAVS), with symptoms including pain and cold sensations in the user's fingers, loss of grip strength, and a loss of sensation in the fingers and hands. An angle grinder with cushioned or vibration absorbent material on the grip can protect hands from ongoing vibration.
- Always wear personal protective equipment (PPE) including safety glasses/goggles, hearing protection, and respiratory protection when grinding.
- Check the grinder before use to ensure the disc and guard are properly attached and tightened. Discs and guards can become loose between uses. Tighten them before connecting the power to the angle grinder.
Our Top Picks
While all that information on the best angle grinders ought to be helpful when shopping, there's really no substitute for hands-on testing. Tom had the pleasure of personally putting all the following angle grinders through their paces during a recent metalworking project. Each of the models reviewed passed our tests and met our standards (see "How We Tested," below), though Tom found some models better for specific tasks than others. Note that all of the following models feature movable guards and screw-in handles.
Photo: walmart.com
The XAG04Z 18-Volt 5-inch Brushless Cordless Angle Grinder is certainly worth checking out by anyone who is in the market for a new cordless angle grinder. This grinder features an 8,500 rpm top speed thanks to its brushless motor and the 18-volt lithium-ion battery. It can handle 4.5- and 5-inch discs.
We found the XAG04Z excellent to work with. While it doesn't boast the highest top speed, the automatic speed adjustment enabled it to maintain speed during tough cuts and grinds. We noticed very little vibration thanks to the rubber over-molded grip and handle, and the lock-on switch proved to be a huge plus. The only downsides we see: Assembling the two-piece handguard was a little awkward, and it would be nice if the tool came with a battery and a charger.
Product Specs
- Disc Size: 5-inch
- RPMs: 8,500
- Power Source: 18-volt lithium-ion battery
Pros
- Automatically adjusts speed and torque settings
- Slow start keeps the tool from jumping
- Lock-on switch
- Very little noticeable vibration
Cons
- No battery or charger included
- Guard is a bit finicky
Photo: lowes.com
When it comes to DIY projects and budgets, not everyone can afford top-of-the-line tools every time. So those hoping to save cash and still get a quality grinder may want to give this corded model from Metabo HPT a look. It uses 4.5-inch discs, has a 6.2-amp motor, and spins at up to 10,000 rpm.
The Metabo HPT's usefulness was somewhat of a surprise. We enjoyed how compact and lightweight it was in hand. The location of the power switch is very convenient, especially during cutting. The lock-on feature allowed me to kick it on and leave it on—very helpful in our project. Our only complaint is that the Metabo HPT lacks the power of other corded models, and the 6.2-amp motor seemed like it could overheat during all-day use.
Product Specs
- Disc Size: 4.5-inch
- RPMs: 10,000
- Power Source: Corded
Pros
- Lock-on switch for long use
- Very light at only 4 pounds
- The most compact of all the grinders tested
Cons
- A little lacking in power compared to other corded models
- The 6.2-amp motor isn't ideal for all-day use
Photo: amazon.com
DeWalt's 20V Max XR Brushless Cut-Off/Grinder cordless angle grinder could be the ultimate upgrade for pros and DIYers who take their tools seriously. This cordless model utilizes the brand's 20-volt Max XR lineup, and its brushless motor spins 4.5-inch discs up to 9,000 rpm.
Our experience with this DeWalt model was just as we expected: great portability and truly outstanding power. It made short work of cutting and grinding, without a cord to get in the way. The grip and handle both feature thick rubber, keeping vibration and fatigue to a minimum. And the safety features are certainly a plus: The electronic brake stopped the disc within 2 seconds (other models can take up to 10 seconds), and simply knowing that there is a kickback brake instilled confidence.
Product Specs
- Disc Size: 4.5-inch
- RPMs: 9,000
- Power Source: 20-volt lithium-ion battery
Pros
- Safety includes two-stage trigger, electronic brake, and kickback brake
- Excellent ergonomics and anti-vibration
- Plenty of power
Cons
- Pretty pricey—but it is an upgrade pick
Photo: amazon.com
KIMO's 20V Cordless Angle Grinder might impress even the most brand-loyal DIYers out there. Between its 20-volt lithium-ion battery, its 9,000 rpm top speed, and the fully stocked kit (which includes grinding, cutting, and sanding 4.5-inch discs), it has just about everything necessary to start grinding.
I didn't have high expectations for the KIMO, but it truly surprised me. First, it had the best slow-start mechanism of any of the models we tested—and not because it lacks power; in fact, it's on par with the Makita and the DeWalt cordless models. Between the affordable price and the loaded accessory kit, we were blown away before we even charged the battery. Our only concern is that it's from a lesser-known manufacturer, so there's a bit of an unknown in terms of the brand and customer service.
Product Specs
- Disc Size: 4.5-inch
- RPMs: 9,000
- Power Source: 20-volt lithium-ion battery
Pros
- Fully stocked kit
- Plenty of power
- Affordable price point
- Terrific slow start
Cons
- Lesser-known brand and customer service
Photo: amazon.com
When it comes to dependable power, a corded angle grinder like this PORTER-CABLE product is ideal. This model features a heavy-duty 7.5-amp motor that spins a 4.5-inch disc at speeds up to 10,000 rpm, providing plenty of speed and power for workshop use.
The PORTER-CABLE grinder felt truly in its element on our metalworking project, handling cuts and grinds nicely. While it doesn't have the most power compared to others on our list, it's pretty close. It's also one of the only grinders to feature a traditional trigger switch, which was easy to use and more intuitive than most. We also really liked the top-mount position for the handle attachment, as it can make cutting much more manageable. The one negative worth mentioning is that vibration control isn't top-tier, so although it can take all-day use, the user's hands and wrists might tire.
Product Specs
- Disc Size: 4.5-inch
- RPMs: 10,000
- Power Source: Corded
Pros
- Top-mounted handle position
- Comfortable trigger switch
- The 7.5-amp motor has plenty of power
Cons
- Vibration control is so-so
Photo: amazon.com
For light-duty projects like wood carving and sanding, grout removal, and other small jobs, Black & Decker's Angle Grinder Tool might be a wise choice. This affordable model features a 6-amp motor that produces up to 10,000 rpm of speed, and it's compatible with 4.5-inch grinding and cutting wheels.
Black & Decker markets this model at light-duty, DIY-type users, and that's where it excels. This very affordable model is easy to use, thanks in part to its lock-on trigger. The three-position handle mounting system works for plenty of scenarios, such as cutting and grinding at unusual angles. Just don't expect the Black & Decker to handle heavy-duty jobs like large metalworking projects for any length of time, as it only has a 6-amp motor.
Product Specs
- Disc Size: 4.5-inch
- RPMs: 10,000
- Power Source: Corded
Pros
- Plenty of capability for the price
- Three-position handle, including top-mount
- Trigger locks into position
Cons
- 6-amp motor is only suitable for light-duty work
Photo: amazon.com
Heavy-duty projects like production welding and cutting require a grinder that can keep up, and DeWalt's DWE402 can handle the job. This burly machine features an 11-amp motor and spins 4.5-inch grinding and cutting wheels at speeds up to 11,000 rpm.
We found the DWE402 to be the ideal grinder for our work, though not everyone will need its power and high-speed capabilities. It cut through angle iron faster than any other grinder, and it made short work of our large, lumpy, amateur-grade welds (though it's definitely a pro-grade tool, and the speed-boosting button on the handle base helped a lot). On the minus side, neither the DWE402's vibration control nor its grip got much attention on the drawing board.
Product Specs
- Disc Size: 4.5-inch
- RPMs: Up to 11,000 rpm
- Power Source: Corded
Pros
- Pro-grade capability
- Very fast and powerful
- High amperage motor for heavy-duty work
Cons
- Not much vibration control
Our Verdict
With its portability and power in mind, Makita's XAG04Z is a great choice for almost any home workshop, though pros may also appreciate this model. And for those who need a heavy-duty model with the power and speed to cut through any weld or metal, DeWalt's DWE402 might be the way to go.
How We Tested the Best Angle Grinders
Sometimes, I have the best job in the world. I've had a project on my plate for months now (building a welding cart), and it just so happened to be the ideal project to test these grinders. I used the same set of cutting wheels for each grinder as well as the same set of grinding wheels to make apples-to-apples comparisons.
I used each grinder to cut through angle iron, switching grinders between each cut until I felt comfortable with the strengths and weaknesses of each model. I recorded myself cutting all the pieces for the welding cart in order to determine how long each cut took and how easy it was to use. After cutting all the pieces, I welded the cart together (rather heavy-handedly, I admit, as it's been a few years since I last welded).
With those big, burly welds to address, I used each grinder to knock them down to flush. Again, I noted ease of use and handling. In the end, I had all I needed to compare the best angle grinders—as well as a cart for my new welder.
FAQs
Even with ample background on the best angle grinders, you might have some additional questions. Here, we answer some of the most common queries about angle grinders, so check for the info you need below.
Q. What kind of tasks can I use an angle grinder for?
The most common uses for angle grinders are metal grinding and cutting, such as steel for welding or metal piping. However, they're also useful for wood carving, refinishing, and other projects. Some farriers even use them to trim hooves.
Q. How are the discs on an angle grinder changed?
First, unplug the grinder or remove the battery. Then remove the nut that holds the disc in place, using the factory spanner included with the angle grinder. Replace the disc and tighten the nut bolt using the factory spanner.
Q. How does an angle grinder operate?
After attaching the correct disc for the job, hold the angle grinder in two hands for safety and security (the tool's initial torque will cause it to jump). Push the trigger down or hit the power switch, and the disc will start rotating. Move the grinder until the rotating disc contacts the material you want to cut or grind.
When finished, release the trigger or switch off the power button and wait for the disc to stop rotating completely before placing it in a safe location, keeping in mind that the disc is still hot due to the friction caused during operation. Unplug the power cord or detach the battery and allow the tool to cool down.
What Is the Best 4.5 Inch Angle Grinder
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