DEWALT 20V 6-1/2 Cordless Circular Saw DCS391

By Robert Robillard on Tool Reviews



DEWALT 20V 6-1/2 Cordless Circular Saw DCS391 Review

It took me a long, long time to warm up to cordless circular saws.  I guess it was the lack of power and run-time associated with these earlier generations saws that made me resist putting down my corded saw for a battery operated one.

Today’s cordless circular saws are more powerful, cut faster and last a lot longer than their predecessors and that is why we at Concord Carpenter are now starting to take them more seriously.

DEWALT sent us their DEWALT 20V 6-1/2 Cordless Circular Saw DCS391 with 4.0 Ah batteries to review and evaluate.    We did a video review on this saw several months back  but with the 3.0 Ah battery pack.

We  the 4.0 ah battery and saw at our workshop to see how it performed not only individually but also in a head-to-head comparison against five other major competitor models.   READ the Head-To-Head Comparison. [coming soon]

First Impression:

The DEWALT 20V  6-1/2 Cordless Circular Saw DCS391 shipped in a solid hard plastic tool storage case that secures “solid” with two durable metal hasps.  Out of the box the DEWALT is a lightweight and compact saw weighing 8 pounds.  out of the box and when set to 90-degrees the blade was dead square to the magnesium base plate as was the bevel gauge was also accurate.   I immediately liked the over sized knobs and levers allow the user to easily adjust and operate the tool.

Attaching the saw blade was extremely easy and dummy proof.  The blade lock button is easy to reach, engage and has no obstructions.  The saw has on board, secure and snug storage for an Allen wrench that removes the blade.

Ergonomics Important

The DCS391 has comfortable rubber over-molded handles and the main handle has an ambidextrous safety trigger.

DEWALT has invested a lot of time, money and research into designing their tools to provide superior balance and ergonomics. These efforts can be seen in their cordless drill handles all the way to the placement of the handles on tools like this circular saw.  Finding that sweet-spot or perfectly balanced grip nirvana and immediately noticed “ergonomic feel” helps the user to make a more accurate cut, improve the overall tool-using experience and most importantly reduce fatigue.

Tool Adjustments and Cutting Specs

The DEWALT 20V Max 6-1/2 Cordless Circular Saw DCS391 has a depth of cut of:

  • 2 1/4″ inches when set at 90-degrees  and
  • 1-5/8″ inch depth of cut when set at a 45-degree bevel.
  • The bevel adjustment will allow the saw to be set at and cut a 50-degree bevel.

The markings for the blade depth and bevel gauge are engraved on the metal housing of the tool.  The blade depth gauge is behind the saw guard and I found it difficult to see.  I typically use this guide as a quick reference for non-money cuts and will always refer to my tape measure or folding ruler for important depth adjustments.

The blade line of site is excellent on both sides of the blade and the saw plate has square cut-out at the front of the base plate for lining up a 90-degree or 45-degree cut.  On this model the cut-out was accurate and lined up perfectly in our tests.


I found the DEWALT DCS391 to be a powerful saw that did not bind easily in framing lumber which was a nice surprise.   I’ve used this saw on the job-site doing light framing and trim work and it cuts cleanly and surprisingly well.  We recently tested this saw by cutting repetitive rips in 3/4-inch Advantec plywood which resulted in the saw making 19.5 eight-foot rips out of the plywood equating to 156 ft of total plywood cut.   In a power, “torture-test,” we ripped LVL stock.   The DEWALT ripped 32-feet of LVL [4 – 8 foot rips] on one battery charge.

NOTE – we tested this saw with a 4.0 ah battery.  This saw does not come with this battery.  You either have to purchase one or already have one in your battery platform.

Possible Negative Issues

In order to shave weight DEWALT uses a magnesium shoe plate and a hard “PVC type” retractable blade guard.  While this guard  seems extremely durable, the fact that it is plastic and at the bottom of the tool, it is highly likely that it ill sustain damage from drops, hard put downs and possible drops in frigid temperatures.

The way the 4.0 Ah battery engages in this tool means that the user has to flip the tool over to view the battery fuel gauge and I did not like it.  It’s not a natural movement and necessitates twisting the too with your  wrist.  The worst part of the  DCB204 4.0 Ah battery is charge time takes 70 minutes.  I’d like to think that with all the technology that DEWALT builds into these tools that they could get that down to at-least 30 minutes.


  • 20Volt
  • No Load Speed 3,700rpm
  • Blade Diameter 6-1/2″
  • Bevel Capacity 50°
  • Arbor Size 5/8″
  • Depth of Cut at 45° 1-5/8″
  • Depth of Cut at 90° 2-1/4″
  • Tool Weight 8.0lbs


Overall Impression

I liked the compact size and lightweight feel of the DEWALT DCS391.   When paired with the 4.0Ah battery this tool has the power and run-time to keep you going on a job-site.  I was able cut framing lumber with ease as well as rip 156 feet of 3/4 plywood.   That is a decent amount of run time and when complimented with a second battery this tool will allow you to work a long time between charges.

How Much and Where to Buy?

The DEWALT 20V Max 6-1/2 Cordless Circular Saw DCS391 sells online here DEWALT-DCS391M1-20V-Li-Ion-Circular for $227.99

Earlier Video Review with 3.0Ah Battery:

Note – We had better line of sight testing on the current model than on the one shown in this video.

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About the author

Robert Robillard

Robert Robillard

Carpenter / Remodeler / Editor / Writer / Video Talent

Robert Robillard is a general contractor, carpenter and operates a remodeling company located in Concord, MA. He is the editor of and ToolBoxBuzz, and a has a weekly column in the Sunday Boston Globe. Rob is a recognized leader in tool and how-to information for building professionals, he hosts the Concord Carpenter Cable TV Show, offering advice on home repairs and maintenance. On his website, Rob uses his knowledge and experience to help and educate on best practices in the remodeling industry. His motto: “Well done is better than well said!”. Contact Rob at:

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