DeWalt DCS391B Review: Compact, Powerful and Portable Circular Saw

DeWalt DCS391B Review

Photo: DeWalt

What We Like

  • Compact and portable
  • Long battery life
  • Powerful high-speed motor
  • Strong magnesium shoe
  • Comfortable grip and handling

What We Don’t Like

  • Battery and charger sold separately
  • The material build could be stronger

Bottom Line

The compactness of DeWalt DCS391B and its high-performance battery make the tool a reliable and flexible circular saw for cutting 2x material with exceptional smoothness and accuracy, all day long.


If you’re looking for a compact, cordless circular saw that offers as much performance as corded models on light-duty cutting, DeWalt DCS391B is your best bet.

It used DeWalt’s 20V Max* Li-ion battery, which is reliable, has high endurance, and recharges very fast. It cuts 2x material smoothly and consistently. The saw’s cordless operation allows for more flexibility in tight spaces compared to large corded models.

DeWalt DCS391B Review

DeWalt DCS391B

Photo: DeWalt

Performance: Powerful, Reliable and Consistent

DeWalt DCS391B may be a battery-powered tool, but it performs at par with most corded models. When paired with DeWalt’s 20V Max Lithium-Ion battery series, this tool produces enough raw power to deliver even on the most demanding cutting tasks.

It has a powerful 460-watt motor, which manages speeds of 5,150 RPM for fast and precision cuts. There are many corded models that won’t even come close to matching this speed.

The speed is harnessed by a 6-1/2-inch carbide-tipped blade that is optimized for cutting 2x material. In the real world, this workhorse will power through light-duty cutting tasks and related materials including plywood, and most 2x12s. Even when working on 2×12 stair stringers, the saw cuts with stellar consistency.

Also, the 6-1/2-inch blade is the ideal complement to the compact tool. It gets into virtually any space you’d need to use a circular saw on. If you will be cutting some tough lumber, especially hardwoods, it’s advisable to upgrade to a fine-toothed blade to prevent kickback or overwhelming the saw’s motor.

Accuracy will always be a top priority for most circular saw users, and DeWalt has addressed this by fitting its saw with a high-strength and lightweight magnesium shoe, which offers the job site durability your tool needs for consistent long-term accuracy.

Design: Compact and Convenient

You will appreciate the compactness of DeWalt DCS391B when it fits in some weirdly tight spaces that other oversized circular saws would not even come close to reaching.

This compactness contributes to the flexibility and maneuverability of the tool, especially when you consider the fact that it is a cordless one.

When adjusting the bevel, you may notice that the knobs are easier to hold than those of other circular saws you may have used, especially 6-1/2-inch ones. This design enhancement goes a long way in simplifying tool operation especially if you’re constantly shifting between different bevel angles.

The shoe could use an increase in the size of measurement markings, but you’ll still be able to read them as they are currently.

Durability: Long-term Reliability across Multiple Projects

DeWalt has made a name for itself in making durable tools you can rely on for the most demanding tasks, and the DCS391B is no exception.

When evaluating durability, it’s important to consider both the tool and the battery needed to supply its power. Starting with the saw, most of its components are made using hard plastic, which is very durable. The blade guard could have been metallic, but it is not any less strong.

Also, the tool’s shoe (base), which is the one subjected to the most stress, is made using magnesium for added strength and durability even in demanding job sites.

It’s clear that DeWalt relies heavily on plastic for the DCS391B’s main material, and some intensive users such as general contractors would prefer a tool with more metal. However, this one is no less durable than metallic ones and its plastic build helps maintain the overall weight at a minimum.

Ease of Use: Superior Comfort and Control

One of the most prominent features of the DeWalt DCS391B is its overmold rubber grip, which is not only large but also provides space and clearance for even large or gloved hands to fit comfortably.

Besides comfort, the same grip is responsible for delivering optimal control and balance when using the tool. Combined with the compactness of this tool, the grips provide superior handling for all-day tool operation, especially because you’ll barely feel its 7-pound weight in the hand.

Also, the circular saw is cordless, its maneuverability and flexibility far outperform those of corded models. Because you never have to worry about a power cord getting in your way, you can get flexible with this tool’s operation. You find it more convenient to carry for offsite projects compared to corded models, which have extra attachments that you need to consider when transporting.

It’s rather disappointing, however, that the tool does not include a blade wrench or on-board storage for one, so you will need to get one of your own and find a way of carrying it with you whenever necessary.

Battery: Reliable All-day Performance

DeWalt DCS391B uses the high-performance and popular DeWalt 20V Max* Lithium-ion battery. Most circular saw users especially recommend the 4.0Ah battery for its long endurance and fast recharge time.

The battery has proven reliable in most of the applications it is subjected to. It excels in light-duty applications which mostly involve 2x material, and such guarantee to maximize the durability of your tool.

Although there are no official numbers on battery life and charge time, a reviewer on the manufacturer’s site noted that when using the 4.0Ah battery, the tool handled a day of light-duty cutting with occasional pauses, and the battery recharge time was less than 30 minutes. Obviously, the battery performance will depend on capacity and usage, but none of the 20V options disappoints.

Disappointing, however, is the fact that DeWalt DCS391B’s amazing battery and its charging tool, are sold separately. Buying the 2 is an extra cost incurred.

Price: Just Right

At less than $100 there’s a lot of value you are getting from DeWalt DCS391B. The power, compactness, and ease of handling that the tool offers are unrivaled by other models in this category.

When you pair it with DeWalt’s famed 20V Max Lithium-Ion battery, you will be getting a full day of light-duty and consistent performance from a lightweight tool that presents no handling challenges.

Even though the battery needs to be bought separately, it is a one-time purchase and you can count on long-term reliability from the accessory.


A compact, easy-to-handle, battery-powered circular saw whose performance has proven reliable across multiple applications requiring cutting on 2x material. 

In the battery-powered circular saw category, DeWalt DCS391B is a worthy contender with its high-endurance 20V Max* Li-ion battery, and powerful, high-speed motor. It will power through most light-duty tasks for an entire workday while promising fast recharge speeds for minimal work interruption.


  • Product Name: DeWalt DCS391B
  • Power: 20 Volts
  • Power Source: Battery
  • Speed (No Load): 5,150 RPM
  • Blade Diameter: 6-1/2-inch
  • Bevel Capacity: 50°
  • Cutting Depth (at 45): 1-5/8 -inch
  • Cutting Depth (at 90): 2-1/8-inch
  • Tool Weight: 7 pounds

Key Features

  • Compact 7-pound cordless unit for superior cutting flexibility
  • Powerful 460-watt, 5,150-RPM reliable motor
  • High-performance 20-volt battery with long endurance
  • Strong magnesium shoe for long-term cutting accuracy
  • Overmold grips provide superior comfort, balance, and control
  • Aggressive bevel cuts support multiple applications
  • 6-1/2-inch carbide-tipped blade cuts 2x material smoothly