DEWALT DC390B 18-Volt Cordless Circular Saw

Great saw.
I’ve been working with a 15 year old cordless Craftsman. This saw is light years ahead in all ways compared to my old one. The technology that goes into these saws has improved dramatically.
I’ve seen several reviews here that complain about the battery life. I use this saw 6 – 8 times a month, so the battery life is not an issue for me. It really does all the cutting I need. On the rare occasion I run a battery out, I have another I switch to and put the 1st one on the charger. I’ve never had to wait for the battery to charge.
90% of the time I use a 24 tooth carbide Diablo blade that really cuts well. I’ve cut 2 x 8 pine, pine plywood, 1 x 6 oak hardwood (with a 40 tool carbide Diablo), cabinet bases, treated 4×4’s that I have to flip and make 2 cuts, bottoms of doors. I’ve also made cuts in many awkward positions that would be very dangerous with a corded 71/4″ saw.
I noticed in the question section someone asking if the tool has a brake. My tool stops well under one second after releasing the power switch.
I do have a corded 71/4″ circular saw, but don’t use it as much now that I have this one. It’s very handy if you want to make a quick cut. I’ve helped the neighbors with some simple one/two cut projects.
In summary, this is a great saw. It’s light, powerful, cuts quickly, easy to use and very handy when a power outlet is not close.

I’m a homeowner, not a carpenter, but I do a lot of basic repair and remodeling work around my house. Right now I’m building a new workspace in the basement, including several new walls and a built-in bench, and that mens I’m doing a lot of framing work. And that means I need a good circular saw. I have a tiny Makita 3-3/8″ circular saw I bout around 15 years ago when it was the only battery powered saw on the market. It was (and still is) great for cutting plywood and other thin materials, but it can’t cut deep enough to saw through 2x lumber, which is about half of what you need a circular saw for in a construction or remodeling project. I used to have a Porter Cable 7-1/2″ saw as well, but it was really more saw than I needed, so I passed it on to a friend. But I still needed a saw that would cut through a 2×4.

A friend gave me a DeWalt 18v drill a few years ago, and I liked it so much I put aside my Makita and bought a DeWalt impact driver, too. Then I found another DeWalt drill, charger, and batteries at a yard sale, so I’m fully committed to the system. When I saw the DeWalt DC390B, I figured if it was as good as the other DeWalt tools it would be all I needed- and it is. First off, it’s a lot lighter than my old P-C saw, and that makes it a lot less fatiguing to use, particularly when cutting overhead. The blade is big enough to cut through 2x stock, so that’s taken care of. At 45 degrees it’ll still cut through a claimed 1-5/8″. The blade are cheaper than the larger 7-1/2″ blades, too.

I don’t know how well this saw will hold up to continuous commercial use, though I expect it would do well in that service. For a homeowner, though, it’ll all the saw I need and then some.

This saw is very useful. Most times i reach for it instead of my corded dewalt. With a good blade and good batteries no trouble to cut 2 by material. This saw obviously has its limits but is great to have on site. great for up on scaffolding… no cords to trip up in. With a good blade and accurate cutting ie: no binding, the battery life is very adequate, its obviously battery operated so it dosen’t run forever but last long enough that it dosen’t feel like your replacing batts too often. One thing that does bug me is that some times the guard doesn’t slide up on skim cuts but not too often enough to be a problem. Over all a fantastic tool. must have around the job site.

I had a 14.4 V Dewalt circular saw for years, and used the snot out of it. It was just the thing to make a cut or two on a roof, or while remodeling when you had to have the power turned off in that area of the house. Eventually, I made the change to 18V tools, and when my last 14.4 battery died, it was cheaper to buy this saw, than 2 replacement 14.4 batteries.
Now, if you realize this is a CORDLESS saw, with it’s limitations set by the batteries, you will be very happy with it. It can cut 2X lumber, not just at 90* like my old saw, but also at 45* (just barely, but it goes through). If you are remodeling your house, and think this will replace a plug-in saw, be prepared to charge a lot of batteries.
That said, I used it to rip a sheet of 5/8 plywood 5 times lengthwise, on a single charge using an XRP battery, and even an 8 foot long CCR treated 2X6 in half, followed by cutting the ripped pieces into 12 inch lengths. It did it all on one battery, but I could tell by the last cut or two, it was slowing down. I don’t have the lithium batteries, but I’d assume they would give more cuts per charge.
Power is surprising. With a good battery, it sailed right through the rip cut of the treated 2X6, which impressed me, as treated wood is usually ‘damp’ from the treatment process, and can be a real power hog to saw through, especially with rip cuts.
The blade included is very good, and seems durable, even went through a couple nails without dulling noticably, but is a multi-purpose blade. You might want to go blade shopping, especially if you want super smooth cuts on trim or moldings.
Blade depth adjustments are quick and easily doe without tools, as are bevel adjustments, and the wrench to change blades is right on the tool. I also like the arbor lock, which holds the shaft from rotating, as you tighten or loosen the arbor bolt. It also has slots for a rip fence (not included, but the bolt that holds it in place is – I just used the fence off my old saw) and works well with one.
One last note, it is a bare tool, just the saw, blade, blade wrench, and the little bolt that locks down the rip fence. No case, batteries, or extra blade are included.