Right off the bat we will be the first to say this test and most others we have read on circular saw blades are pretty flawed. To do it right we would love to take off a week of work and do nothing but cut stuff morning, noon and night. Say 20 of each blade that we could use until they went completely dull ina variety of materials 2”x4” pine, chipboard, shingles on plywood and a test with a nail every 100ft. We would then make a grid and score each blade by application, that way a roofer could judge what is most important to them while framers could see what they care about. In real life for most applications people are not as hard on blades as we have seen in testing so it would be great to get an idea how these blades would handle in several different real world environments. You unfortunately aren’t going to read that here, we have instead put these blades through one of the most abusive test we could think up because of limited time and resources.
One other variable that might also skew your view towards our comparison test is the Ned Flangers effect, that’s right we are using our Milwaukee left handed circular saw 6391-21 ($139, Ohio Power Tool). This means the blade gets put on upside down to up cuts and we assume performance would be the same but really have no idea how that might affect blade performance. We noticed Freud and Irwin do not have directional markings on the left side (backside) of their blades; shall we take that as you have no concern for the safety of left handed users?
For our test we choose the brutal task of deck screw cutts to compare these blades, which for lesser quality blades could be lights out on the first contact. Hits like this will often cause serious damage to carbide teeth and will eventually knock the entire tooth off which is what we found in our test. We put two deck screws into the end of the 2”x4” then cross cut twice per set of screws before clearing the piece and driving 2 more screws.
Initial Blade Feel
As expected the DeWalt Precision Framing Blade DW3199 ($19, Amazon) felt very smooth and went right through the screws with surprising ease. The resin filled slots cut down on vibration and anti-kickback shoulders looked to be the most aggressive of the 4 (although all of them had a similar anti-kickback feature). The claim for a harder plate and sharper carbide teeth seems very accurate.
The Bosch Daredevil Framing Blade DCB724 ($9, Ohio Power Tool) also did a very nice job with a noticeable smoothness on the initial cuts through the wood and screws. The Bosch features a new sharpening geometry with 3 cutting edges that do feel like you are getting a smoother sharper cut. The Bosch also features a hardened plate and anti-kickback shoulder making the feel between the Bosch and Dewalt blades honestly very hard to say one was better than the other.
The Freud Diablo Framing Blade D0724R (D0724A $9) in our region of the country this is the most popular choice for framers, roofers and general construction. Many of the features of the new Bosch and DeWalt blades are aimed to combat the Freud blades. The harder plate, thin kerf, blade coating for smoother cuts and anti-kickback are all features that helped make the Diablo so popular. On initial cuts it was very smooth as well however if we are being picky, ranking against the other it would probably fall just slightly behind the newer Bosch and Dewalt blades for speed and smoothness.
The Irwin Marathon Blade 14030 ($13, Amazon) was the worst performer in our test but still a much better performer than we have historically used for circular saw blades. The Irwin Marathon does features anti-kickback technology but did not have an anti-resistance coating or any vibration reduction. We will mention since we received these blades originally Irwin has released a new WeldTec Marathon Blade which should be more competitive with longer blade life and faster cuts.
Best Results from Deck Screw Test
DeWalt – 64 Screw Cuts
Bosch – 59 Screw Cuts
Freud – 80 Screw Cuts
Irwin – 45 Screw Cuts
In this test the Freud was actually able to handle the most screw impacts, a test to their solid durability. All seemed to do well through 20-30 screws but once teeth began to chip and fracture the blade would go south pretty quickly loosing entire teeth. The Freud seemed to do the best job at holding onto the carbide teeth even after significant portions of carbide were gone. When we got to the end of the Freud blade almost all the teeth remained but were completely worn away. The Bosch and DeWalt both seemed to become unusable with teeth that still have a decent amount of material left.
Until know we have regrettably mostly used middle of the road circular saw blades. So when you are use to driving a Honda Civic and you are given the opportunity to test drive a Porsche, Ferrari & Lamborghini all of them are going to be leaps and bounds ahead of what you are familiar with. Basically all these circular saw blades are excellent, and if you are buying a single blade for your saw in the garage you use for an occasional job any of these 4 blades are going to be an excellent choice. For pros going through 25 bulk packs like chewing gum, the right blade could mean a big difference and might be worth your time to test a few blades for your application.