DEWALT DCS391B

DEWALT DCS391B

By DEWALT · Circular Saws · Power Tools

  • No-load speed 5150 rpm
  • Blade diameter 6-1/2 in
  • Bevel capacity 0 to 50 degrees
  • Weight 7.1 lb
  • Voltage 20V MAX

Lowest price seen
$87.28
from $87.28 at eBay · Checked Oct 14, 2026

Prices are snapshots. Check the current price with the store.

Summary

A lightweight brushed-motor cordless circular saw for DIYers and hobbyists who already own DEWALT 20V MAX batteries. The battery and charger are sold separately, so factor that into the price before you buy.

Strengths

  • Lightweight at 7.1 lb and easy to handle for extended cuts.
  • Blade-left design gives right-handed users a clear sightline.
  • Magnesium shoe provides durability and long-term cut accuracy.
  • 5150 RPM is sufficient for light-to-medium-duty cutting.
  • Rubber overmolded grip is comfortable.
  • 3-year limited warranty with 1 year free service.

Weaknesses

  • Brushed motor is less battery-efficient than brushless alternatives.
  • No positive bevel stops at common angles (22.5°, 45°).
  • No LED work light, no dust port, no rafter hook.
  • Ripping is slow; 43 s for a 10-ft 2"x12" rip in TechGearLab testing.
  • Depth adjustment indicators are awkwardly placed.
  • Not recommended for daily or professional use.

Verified specifications

ModelDCS391B (bare tool).
Voltage20V MAX (18V nominal).
Motorbrushed (not brushless).
No-load speed5150 RPM (manufacturer spec); manual lists 5250 RPM.
Blade diameter6-1/2 in (165 mm).
Arbor size5/8 in.
Bevel capacity0-50°.
Max depth of cut at 90°2-1/4 in (manufacturer spec); TechGearLab measured 2-1/8 in.
Max depth of cut at 45°1-5/8 in.
Weight7.1 lb (manufacturer spec); 7.2 lb (DEWALT Canada); 6 lb measured without battery (TechGearLab).
Blade sideleft (sidewinder).
Shoe materialmagnesium.
Griprubber overmolded.
LED lightno.
Dust portno.
Laser guideno.
Blade brakeyes.
Rafter hookno.
Included(1) DCS391 saw, (1) 6-1/2 in carbide-tipped blade.
Battery/chargersold separately.
Warranty3 Year Limited Warranty, 1 Year Free Service, 90 Days Satisfaction Guaranteed.
Dimensions15.5 W x 8.5 L x 10.5 H in.
Full research notes and sources

Cutting performance

TechGearLab’s instrumented testing scored the DCS391B 56/100, ranking it #8 of 10 circular saws. Sub-scores: Bevel 7.6/10, Cross Cuts 4.3/10, Ripping 4.5/10, Metal Cuts 5.0/10. Measured performance: 6"x12" cross cut in 5.00 s (framing blade) and 6.5 s (finish blade); 2"x12"x10’ rip in 43 s; 2" galvanized steel pipe in 8.87 s; 16-gauge sheet metal in 27.0 s. The saw was tested with a 5 Ah battery. TechGearLab recommended it for casual users with occasional projects around the house or weekend DIY users, not for daily users or professionals, and noted it “requires patience for longer cuts”.

Plumb and Lined gave the saw a perfect score after 2 years of daily use, praising its 5150 RPM, blade-left design, and light weight (7 lb with battery). This is a single-reviewer assessment, not an instrumented lab test.

Design and usability

The blade-left design gives right-handed users a clear sightline of the cut line. The magnesium shoe provides durability and long-term cut accuracy. The rubber overmolded grip is comfortable. However, there are no positive bevel stops at common angles (22.5°, 45°), and the bevel scale is engraved on magnesium with no contrast fill, making it hard to read in some lighting. Depth-of-cut indicators are awkwardly placed; users report setting depth by eye against the blade rather than using markings. There is no LED work light, no dust collection port, no laser guide, and no rafter hook.

Motor efficiency and battery platform

The DCS391B uses a brushed motor, which is less battery-efficient than brushless alternatives like the DCS565B and DCS570B. Reddit users describe the DCS391 as “vastely outdated” due to its brushed motor. The saw is compatible with all DEWALT 20V MAX batteries, but the battery and charger are sold separately. Battery life in real-world use (cuts per charge) has not been independently measured.

Is it worth it?

At <= $99, the DCS391B is a strong value for occasional/DIY users who already own 20V MAX batteries: lightweight, capable, 3-year warranty, magnesium shoe. $100-139 is fair value; compare brushless alternatives (DCS565B) which offer better battery efficiency. $140-159 is weak value for new buyers; the brushed motor and lack of modern features (LED, dust port, positive stops) make it hard to recommend over brushless competitors at the same price. Above $159, the DCS570B (7-1/4 in blade, brushless, positive stops) is a better choice. TechGearLab lists $159 USD list price (2026-02-16). Empire Rigging lists $159.00. Global Industrial lists $165.95 (with conflicting 3700 RPM spec). The bare-tool price is typically lower than kit versions (DCS391P1 with 5 Ah battery and charger). Battery and charger are additional costs if not already owned.

Which model this is

This page covers the DEWALT DCS391B, a 20V MAX cordless circular saw (tool only, battery and charger sold separately). It is a brushed-motor sidewinder with blade on the left, 6-1/2 in blade, 5150 RPM no-load speed, 0-50° bevel capacity, magnesium shoe, and carbide-tipped blade included. The “B” suffix denotes bare-tool variant; kit versions (DCS391P1, DCS391M1) include battery and charger. Do not merge with DCS570B (7-1/4 in blade, brushless), DCS565B (brushless 6-1/2 in), or DCS393 (different model). The Amazon listing is ASIN B007NVSTO8.

Sources

Manufacturer:

Independent reviews:

Owner reports:

Parts and stores:

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