Angle grinders are an integral tool for many trades including the steel, automotive, masonry, and landscaping trades. Used for cutting and grinding steel, concrete, stone and masonry, angle grinders require significant power to get the job done. Until recently angle grinders were not considered to be a viable cordless tool. With recent advancements in brushless motors and high capacity batteries most tool manufactures now offer solid cordless angle grinders capable of tasks that previously required a corded tool.
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With the addition of accessories angle grinders are an incredibly versatile jobsite tool that can perform a wide variety of tasks including: sanding and polishing wood, cutting drywall and plaster (with minimal dust) and leveling old concrete floors.
For this Head-to-Head the focus is on the more popular smaller 4-1/2&#; to 6&#; category which is well suited for the cordless platform.
In order to keep the tools in this Head-to-Head somewhat similar each manufacturer was given a range from 18-22 volts, 4-1/2&#; to 6&#; diameter, and battery packs ranging from 5.0 to 6.2 Ah. The following cordless angle grinders were included in the test:
The challenge for any Head-to-Head testing is developing the testing and evaluation criteria in order to create a valuable comparison for users. Obviously there are hundreds of tests that could be performed, however with limited time and resources for this article we chose the following tests as a good baseline comparison.
Each category gets ranked and the results from each are then used to determine and overall winner for the Head-to-Head.
While some of the categories above are subjective, some tests can be measured to give a relative comparison for each tool. As stated earlier, there are literally hundreds of tests that can be done to compare any tool. For this evaluation two tests were selected to give a good relative, measurable comparison including: run-time and performance (speed cutting). While this is an extremely narrow set of tests, we felt it was a good baseline. Clearly run-time is hugely important with high demand cordless tools like grinders, and productivity is always an important benefit to consider when buying any tool so hence the speed of cutting test.
For this evaluation several types of steel and concrete were used in order to get a good perspective on performance. The following materials were included in the testing:
This section of the evaluation considered ten different categories including:
Variable Speed
This is a straight-up comparison of features, a tool gets a &#;1&#; if it has the feature, and a &#;0&#; if it does not. The tool with the highest ranking is the best in this category.
There are few standout features that affect performance and safety. Not all the grinders had these features, and below we listed these &#;stand-out features&#; and the grinders that have them.
Finishing in a tie for first place were the Bosch and Makita grinders. The Bosch illuminated controls were definitely a favorite of our crew and would give it a slight edge over the Makita if we had to choose. Tied for second was DEWALT, Hilti, and Milwaukee. And in third was a tie between Metabo and Metabo HPT.
In an effort to remove as much human user variability in our test results we look to build testing jigs/rigs that provide repeatable and fair test results. This helps eliminate questions about whether or not a tester is pushing harder or holding a tool at a strange angle which might alter the results. However, with limited time and resources it&#;s not possible to build a jig for each of our tests. Below is a list of the testing stations for this Head-to-Head. The first station used a jig, while the remaining two stations used the angle grinders free-hand. The two free hand stations were used to give our testers hands on experience for the subjective rankings in ergonomics.
The three testing stations:
Each grinder used a new Metabo, metal abrasive cut-off disc, and each disc was changed out after 17 cuts.
In this test most of the tools have very similar voltages and battery pack sizes (amp-hours). However, to truly compare them as close as possible, using the total watt-hours (Total available energy) and normalizing the results helps level all of the tools. Watt-hours is simply calculated by multiplying the voltage by the amp-hour rating on the battery pack. In the specification section above we&#;ve listed the Watt-hours for each tool based on the voltage and pack size. Six of the tested tools have watt-hour ratings of 108, so the other results will be normalized to that. For example, Metabo has a watt-hour rating of 99. So the results for Metabo will be factored up by 108/99 or approximately 9%. Metabo has a 5.5 Ah pack, if it had a 6 Ah pack like the others it would more than likely do about 9% more work.
As you can see above DEWALT had the most cuts per charge with 50, followed closely by Metabo with 49, and Hilti with 47. 50 cuts through 5/8&#; rebar with a cordless angle grinder is pretty impressive! Clearly these new generation cordless grinders have the ability to do a serious amount of work per charge and keep up with jobsite demands.
The next test was the performance or speed test. In this test the time to cut 5/8&#; rebar was measured throughout the run-time testing and averaged for each tool to calculate the average cut time for 5/8&#; rebar. These results provide some insight into not only the cordless angle grinders disc speed, but really the combination of torque and speed which results in the overall time to complete the task.
As you can see below Metabo came in first place followed by Milwaukee and Ryobi. Metabo was nearly twice as fast than the Ridgid.
While measuring run-time and cut speeds, the external temperature of each angle grinder was measured using a thermal imaging tool. For high demand cordless tools like grinders, heat can be a big problem. Below is a chart showing the maximum measured temperature for each tool during the cutting tests. The temperatures were not used in scoring but the information is certainly valuable and worth sharing. As the chart shows, the Metabo ran quite a bit cooler than the other grinders at 92 deg. F, and the Makita topped the chart at 125 deg. F.
For the ergonomics evaluation the team evaluated the following: grip, side handle, blade guard, blade guard mount, disc change, power switch, battery change, vibration, balance, maneuverability, and brake speed. For each category, the team ranked them 1, 2 or 3, (1 being the best). For the brake speed we measured the time for the disc to come to a full stop (shown below in the chart), and ranked them 1 for grinders under 1 second, 2 for grinders that stop between 1 and 2 seconds, and 3 for a brake that took longer than 2 seconds.
Much of the ergonomics evaluation came from team members using the grinders at the thin-set and grinding station. Each team member used each grinder grinding thin-set, grinding steel, and cutting steel to get a relative comparison of each tool.
Each category was totaled up (see table below), and the lowest score being the best. As you can see there was a tie for first place between Hilti and Makita. Second place went to Bosch and Milwaukee finished in third.
For this Head-to-Head we&#;re using a different approach with the pricing evaluation. In the past we tried to use kit pricing, and if kit pricing wasn&#;t available, we&#;d use bare tool plus battery pack and charger. That seemed to be a bit inconsistent so this time the pricing is based solely on the bare tool. Every manufacturer offers bare tool pricing so this way the battery pack costs are not a factor.
For more Cordless Angle Grinder Manufacturerinformation, please contact us. We will provide professional answers.
Below is a chart showing the pricing (at the time of publication) of each of the bare tools. There are three distinct groups, around $100 includes Ryobi, Bosch and Ridgid. Just under $200 is DEWALT, Hilti and Metabo HPT, and the three tools over $200 include Makita, Metabo and Milwaukee. As we always do, these will be ranked on just the cost, as cost is a factor for many users when combined with the other results. Finishing in first place is the Ryobi, followed by Bosch and Ridgid in second, and DEWALT in third.
As usual the Head-to-Head competition was very close but at the end of the Day the Tool Box Buzz Crew must pick a winner and the DEWALT DCG413 is our winner of Best 4-1/2&#; to 6&#; Cordless Angle Grinder.
The DEWALT DCG413 edged out the competition by one point. It finished first in run-time, tied for second in features, third in price, and fourth in ergonomics and speed. Our team felt it was a well balanced, feature filled grinder with plenty of power and run-time to get the job done.
Finishing in a close second was the Bosch GWS18V-45 finishing first in features, second in ergonomics and price, fifth in speed and sixth in run-time. Third place goes to the new Hilti AG 4S-A22 that just hit the market. It finished first in ergonomics, tied for second in features, third in run-time, fourth in price, and seventh in speed.
Below is a summary table of all the final rankings.
Cordless angle grinders are the real deal now! When it comes to smaller size grinders in this category the run-time is sufficient for lots of tasks and when paired with an extra battery most can keep workers in the game all day. The benefits of not dragging around a cord are numerous and the freedom certainly increases productivity and safety.
We get lots of comments about how we make the final rankings. As we&#;ve stated, there are hundreds of ways to compare tools. The good news is we&#;ve openly shared ALL the data from our tests, and you can rank the tools however you want. Don&#;t care about the price? No problem eliminate that from the matrix above and re-rank them. Hopefully you&#;ll find this Head-To-Head useful in comparing a wide range of small cordless angle grinders.
Who here can help me with some buying advice for some new Makita 18V swag?
Particularly interested in an cordless Angle Grinder, I narrowed it down to the Makita DGA517.
Does anybody have any experience and thoughts on this model?
Especially, how&#;s the runtime?
Many people seem to be in the &#;get corded&#; camp, but I&#;m not going to use it for hours on end, so good enough runtime is good enough.
Regarding the Makita Multi-Tool;
I&#;m debating between the Makita Multi-Tool DMT51 and DMT52.
The DMT52 has a lot of plusses over the DMT51, expect for Starlock, those blades are expensive like hell.
Oslo Tool sells an Starlock adapter which you can use to attach the standard OIS bladed on an Starlock machine, it looks high quality and only costs something like $40.
https://www.oslotoolcompany.com/products/makita-dtm52z-xmt04-adapter
Does anybody have any experience with this or any suggestions?
How&#;s the tool in general? I&#;ve read about some quality control problems.
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For more information, please visit Corded Power Tools.