As part of our oscillating multi-tool blade comparison (which is funded by Bosch), the first thing we looked at was cutting speed for each of the three Bosch, Dewalt, and Imperial metal-cutting blades.
In our nail-cutting tests, what we found was that Imperial’s metal-cutting blade is fastest at first, but Bosch’s carbide-toothed blade took the lead after a few nails and had consistently short cutting times.
Cutting performance and blade wear will be discussed in continued coverage of the comparison testing.
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Test Fixture
The final testing setup was discussed in Part 4 of the comparison post series. In short, an oscillating multi-tool was secured to a horizontal sled, with speed set to maximum (~20,000 oscillations per minute). Each blade cut through 16D nails, with a vise set up to hold one nail at a time in the same position.
Here’s a quick video of a single nail-cutting test run:
http://youtu.be/Mcww6rBjN2Y
Measurements
The easiest way to time cutting speed was to look at the current and power draw of the oscillating multi-tool that is recorded before, throughout, and after each cut. Video footage was also used to verify the time it took for a blade to make each nail cut.
The original plan was to record the time it took for each blade to make 20 cuts, with a diagram showing if and how the time of cut changed for each nail. However, the blades did not all last for 20 cuts, and so we looked at fastest cutting speeds for each blade.
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For these measurements we took the cutting speed for the BEST performing blades of THREE test runs for each blade.
Results
Bosch OSC114C Blade (Carbide Teeth)
Bosch’s quickest time of cut was 5.66 seconds to cut through a 16D nail. After that, cutting speed was typically between 6.5 and 7.5 seconds.
By the time the 20th cut was made, cutting time was still just 7.74 seconds.
Dewalt DWA4209 Blade (Bi-Metal and Titanium Coated Teeth)
The quickest time of cut speed for a Dewalt blade’s first cut was 12.37 seconds. The same blade was not able to make a second cut.
Imperial Storm MMT340 Blade (Bi-Metal and Titanium Coated Teeth)
Imperial’s STORM metal-cutting blade actually took home the medal for top speed. The quickest speed for first cut was 4.35 seconds.
However, the speed didn’t last long. The second cut was pretty quick, and the blade cut through its third nail in a little over 6 seconds.
By the fourth cut, cutting time had increased to 9.98 seconds. After that, the Imperial blade started producing a lot more dust than chips and failed.
Summary
Imperial’s blades were consistently faster when fresh, but their better cutting speeds were not sustained.
Bosch’s metal-cutting blades provided fastest speed of cut overall, except for when making those first few cuts. Bosch’s blades quickly surpassed the Imperial blades after just a few cuts.
The Imperial blade with the fastest cutting speed had shorter cutting times for the first three nails. Starting with the fourth nail, the Bosch blade had the fastest cutting speed.
The best of three fresh Dewalt blades took more than twice as long to cut through a nail.
So Which Blade Had the Fastest Cutting Speed?
Nail #1: Imperial
Nail #5: Bosch
Nail #10: Bosch
Nail # 20: Bosch
It’s not entirely accurate to say that the Bosch blade had the fastest cutting speed in regard to the 10th and 20th nails. Why? Because the other brands’ blades came nowhere close to cutting 20 nails at all. Only one of the Imperial blades came close to cutting its 10th nail, and it wasn’t quick or without a little smoke and a lot of sparks.
Test Bench vs. Real-World Expectations
In the testing apparatus, a short section of cutting teeth are repeatedly used to cut each nail. This allows for more controlled testing, but it also accelerates blade wear. This amplifies any differences in cutting speed or blade performance. Even so, these results should translate well to what you will see when using blades in a handheld multi-tool for real-world cutting applications.
You should also remember that, when making handheld cuts, you can use the entire length of a cutting blade’s edge if you move the oscillating tool back and forth horizontally. So even if you break or dull a few teeth in one section of the blade, you can sometimes use another part of the blade before the blade needs to be replaced.
Conclusion
The Bosch blade is not fastest at first, but the gap between Bosch and Imperial cutting speeds disappears rather quickly after just a few cuts. Beyond the first few cuts, Bosch’s blade always had the fastest cutting speed.
The best way of putting this is that the Imperial MMT340 blade has the best sprinting speed, and the Bosch OSC114C blade is the marathon winner.
Buy Now: Bosch OSC114C, Imperial MMT340, Dewalt DWA4209 via Amazon
Table of Contents
Part 1: Comparison Overview
Part 2: Testing & Measurement Tools
Part 3: Test Setup Optimization
Part 4: Final Test Setup
Part 5: Best Cutting Speed (current page)
Part 6: Cutting Performance
Part 7: Durability
Disclosure
Bosch funded this comparison testing project. They did not tell us what to say, and made it clear that it was not their intent to influence the results in any way. We were given full control over how the OMT blades were to be tested, and how the results were to be presented.
Ktash
Amazon’s deal of the day is Bosch MX25EK-33 120-Volt 33-Piece Oscillating Tool Kit for $119. If they had the stacking box, it would be an even better deal. It does have a case, though.
Ktash
Also an extra 20% off the blades till the 24th.
http://www.amazon.com/gp/feature.html/ref=amb_link_421199142_1?ie=UTF8&docId=1002842631
Farid
Upon looking at the photos, I am not surprised. The cutting teeth on the Dewalt and Imperial blades are directional. That might work well in a handsaw, hacksaw, or band saw, where the applied pressure and movement is directional. Not so in this case . On a hacksaw, if you put the blade backwards and try to use it, it will dull the teeth quicker. My guess is that this what happens here. As the blade is raking backwards across the nail, it ruins the teeth without producing much cutting. The teeth tips will tend to bend inwards, thus reducing the cutting ability and increasing friction with each stroke, which leads to excessive temperature, which leads to blade weakening. It’s a loosing battle from the start.
As an engineer, and tool lover I appreciate a lot what goes in designing these products, but I am surprised to see this from Dewalt.
Stuart
Imperial and Dewalt blades have thin and wavy cutting edges, while the Bosch blades have thicker cutting edges. The thinness of the Imperial and Dewalt blades should help ease frictional forces by some amount.
Heat could be a factor, but during the slower part of testing, blades were given more time to cool down between cuts. My thoughts mirror yours, that the directional teeth helped to hasten dulling and blade wear, but the hardness and durability of the blade cutting edges also contributes greatly to this.
I don’t think I’ve seen any Bosch blade spark while cutting, but I cannot say the same for Imperial and Dewalt blades. I’m sure the Bosch blades might spark in a similar manner once they reach a certain point of wear, but I haven’t gotten to that point yet.
Garrick
Trying to figure out the cost per nail cut, I wonder how many nails can be cut before the blades (the Bosch mainly) becomes impractical.
I would say that as the cutting time approached 20 seconds, the cost of the time plus wear and tear on the tool and hands, would make it worthwhile to replace. Of course, the more nails that can be cut, the less the cost per cut, and therefore the length of time it takes, before rationally replacing a blade, would be smaller.
There is also some time cost in changing blades, and in buying them as well.
Stuart
At 20 seconds per cut, a dulled blade would produce much more dust than chips. You can hear a difference in sound as this happens, which indicates blade failure.
According to my lab tests (as opposed to real-world handheld use), Bosch’s blade offers the lowest cost per nail, and by a significant difference.
Joe M
In a way, this is kinda apples and oranges. Carbide is always going to be better on Metal applications than Bi-Metal Titanium Coated. The tooth direction is significant, and added, or perhaps exacerbated, the wear of the blades. I am disappointed at the DeWalt results, as I’m a DeWalt devotee. That said, they’ve never produced these products before. So, for a first time, it’s better than I would expect.
Carbide, Non-directional Teeth were what won this. If there was a Carbide blade to test of the other two brands, then it wouldn’t be as much of a foregone conclusion as this was. Carbide will last longer, where manufactured sharpness of the Imperial blades probably is what gave them the edge in the beginning. Once those directional blades were deflected a little, that edge was lost, and the Carbide won by consistency.
This says a lot about how blades are made! Perhaps not so much about brands, but DEFINITELY the benefits of how blades are made for a job!
Thanks Stuart!
Stuart
I considered that comparing the blades is somewhat apples vs. oranges, but these are the three brands’ metal-cutting blades, and all are comparatively priced.
The direction of the teeth might help the blades to cut lighter duty materials faster. Initial runs were done with lighter and heavy metals, including copper pipe and stainless steel threaded rod, and I found that nails were the most consistent to cut. Plus, this is without realm of what users will be looking to cut – nails, screws, and other such metallic objects and materials.
The three blades have different designs. Imperial’s is wider, Dewalt’s has a thin and wavy cutting edge like Imperial’s, and Bosch’s has thicker and symmetrical carbide teeth.
While I would LOVE to do some modeling that would help sort out why the blades all perform differently, I narrowed down the scope of the comparison to ask very specific questions.
Which blade cuts fastest? Which blade cuts with the least amount of effort? Which blade wears the slowest?
Answering Why? is a rather loaded question, one I don’t have the resources to explore. The ultimate question I sought to answer was “Which of these 3 comparably priced metal-cutting oscillating blades are best?”
dan
Carbide blade was always going to be the best performer as Bosch wouldn’t have funded this test if their product was rubbish, but Bosch blades are usually very good and as these say Swiss made that’s a sign the blades will be good.
Stuart
That’s probably true.
As you mentioned, the Bosch blades are indeed made in Switzerland, while the Imperial blades are made in the USA, and Dewalt blades are made in the USA of US and foreign materials.
Bruce
Today I needed to make some 4×6″ cuts out of a 18 gauge sheetmetal duct. I wanted to try the oscillating tool because a recip saw will often make a hash of things inside the duct and it’s also a real pain to start the plunge cut.
The local hardware store only had imperial blades. A three pack of 18tpi (Storm blades, titanium, yada yada yada) couldn’t finish the job before the teeth were all gone. I ended up finishing the cuts with a recip because I didn’t want to drive back to the hardware store. I’ll be interested to see how the bosch blades hole up in a similar test.
John
Has anyone ever tried cutting out the back of a bocsh blade so that it will work with the dewalt tool-less change system?
Monte
Thanks for this test Stuey ! Just ordered one of these Bosch blades…
Builder integrity
The disclaimer that Bosch funded the test should have been the first sentence on the post, not the last. Obviously, Bosch has a business relationship with the website and they don’t have to tell you what to do to design a test that makes them look good. It’s implicit.