DEWALT DWA4242 Diamond Flush Cut Oscillating Blade

For me, this just became the hands down, perfect blade for cutting through cementitious plaster walls. I have a 1939 built house that I am rewiring, and finally got sick of using a sawzall to open up the walls to run wire. A sawzall ended up doing more damage as I cut through one side of each lath, and then started cutting on the opposite side of each lath, and the vibrations ended up ripping out more plaster than I intended.I burned up 3 bimetal blades on my Multi-tool, and didn't even get one opening cut, before deciding to give this Diamond blade a try. For $10 it was worth a try.I have a really high cement and fine aggregate makeup to my plaster walls with no wire reinforcing, and this blade is perfect for my application. Clean, easy cuts through the plaster, then I have to switch out to the wood blades to get through the lath, but it became an infinitely easier job with better results.I cut (6) 12"x12" openings initially (so 24 lf of cement plaster) and I cannot tell any sign of wear. That alone is worth the $10 per blade.

For my specific purpose (grinding concrete), this blade is one of the best low-cost, high-convenience discoveries of my business. The blade is long enough to reach into/under door jambs (even with door hung). Being diamond instead of carbide, it cuts concrete well and for a good while and is aggressive but doesn't gouge the concrete. I have 3 cordless oscillating tools (Milwaukee's blade change process is insanely frustrating-- stay away from that one! DeWalt is a 3-second dream to change blades so I have two of those and love them).Anyway, this blade is where it's at for cleaning up concrete corners and reaching under things (drywall, door jambs, drains, etc.). This blade worked so sell that I was able to effectively buzz across a door threshold and along a short section of wall as if it were a fine cup wheel. The longer-than-normal length of the blade (compared with HD consumer grade) probably helped with its longer throw during oscillations.

This works with Ridgid tools and works really well. However, it does not last if you have lots of grout to remove and will heat up quickly causing it to chip or break. So be sure to order extra. Mine handled about 12 inches of a 1/16th wide grout line. Mine also broke at the head but can still function (see photo). It does work between 1/16th inch gaps and will also cut tile at a slow pace. Obviously you need to use caution when using anything that has a blade moving at high speeds, but be careful especially in tight corners and tiles being close together. This should be the tool that handles the work in the open while a manual hand grout removal tool should be for corners and corner joints.

I received my diamond oscillating blade today and put it to the test. I was installing an outlet in the wall of my 1925 house with plaster over metal lath embedded cement over wooden lath. I cut right through the cement and then the metal lath, and then I switched to a carbide wood blade to cut the wood lath. The Diamond blade did very well, cut the plaster, concrete and metal lath with no problem, and no apparent damage. Repeated use would tell the longevity, but it did the job that I bought it for, and for that alone, was well worth the price.

Worked great to cut out tile grout for a couple of shower shelves.

I love the concept of this blade but it didn't hold up very long. It was great for removing grout and thinset. If you need to use it for spot applications I highly recommend it. If you need something for continued heavy duty use, this isn't the blade for you.After about 45 minutes of stop-and-go usage removing thinset and grout from the back side of tile I wanted to reuse, the diamond coating started chipping away. Having about half the diamond coating left, I continued working with one end of the blade. After maybe 10 more minutes, the blade itself began to break apart. I was disappointed to say the least because the blade was working very well on the grout.

Do not recommend! This blade is useless. It. hardly even scratched our porcelain tile, much less cut anything. And we have a nice oscillating saw that we used it with. Disappointed.

I had to cut glass tile that was put in to close to the outlets on the backsplash and it worked. Very happy with my purchase. Just keep water near to cool off the blade so it doesn’t dull quickly.