Angled profile view of the DEWALT DCG400B ATOMIC 20V MAX brushless cordless 4-inch angle grinder highlighting the slim ergonomic body, electronic brake system, and protective wheel guard.
Side profile of the DEWALT ATOMIC 20V MAX cordless angle grinder showcasing the safety paddle switch and the durable yellow and black housing designed for tight spaces.
A front-angled view of the DEWALT 4-inch brushless angle grinder displaying the adjustable Type B protective guard and the high-performance motor branding.
Top-down view of the DEWALT ATOMIC 20V MAX 4-inch angle grinder detailing the industrial labeling and the compact profile engineered to be 13 percent lighter than pneumatic grinders.
Rear angled view of the DEWALT 20V MAX brushless angle grinder showcasing the battery port and integrated debris filters to protect the motor during heavy-duty metalworking.
Annotated diagram of the DEWALT DCG400B angle grinder pointing out key performance features including the electronic brake, anti-rotation system, paddle switch, and tool connect chip ready port.
Kit overview for the DEWALT DCG400B bare tool, listing the angle grinder, wrench, Type B guard with Type A clip-on, two Type 1 wheels, and various mounting flanges.
Action shot of the DEWALT ATOMIC 20V MAX angle grinder cutting through a structural steel beam with sparks, demonstrating its lightweight and powerful cordless efficiency.
A professional fabricator using the DEWALT 20V MAX 4-inch cordless angle grinder to grind a steel component, highlighting its design which is 29 percent smaller than standard DEWALT grinders.
Promotional image for the DEWALT DCG400B angle grinder resting on a metal surface, emphasizing the anti-rotation system designed to maximize operator control during binds or stalls.
Close-up action shot of the DEWALT brushless angle grinder in use with a gloved hand, emphasizing the electronic brake designed to stop the wheel in 1.15 seconds for enhanced job site safety.
A professional tradesperson using the DEWALT DCG400B cordless angle grinder to cut a large metal pipe, highlighting that the tool delivers 44 percent more power than 0.7 HP pneumatic grinders.
DEWALT® Product Guides - Grinder Basics promotional how to video
Angled profile view of the DEWALT DCG400B ATOMIC 20V MAX brushless cordless 4-inch angle grinder highlighting the slim ergonomic body, electronic brake system, and protective wheel guard.
Side profile of the DEWALT ATOMIC 20V MAX cordless angle grinder showcasing the safety paddle switch and the durable yellow and black housing designed for tight spaces.
A front-angled view of the DEWALT 4-inch brushless angle grinder displaying the adjustable Type B protective guard and the high-performance motor branding.
Top-down view of the DEWALT ATOMIC 20V MAX 4-inch angle grinder detailing the industrial labeling and the compact profile engineered to be 13 percent lighter than pneumatic grinders.
Rear angled view of the DEWALT 20V MAX brushless angle grinder showcasing the battery port and integrated debris filters to protect the motor during heavy-duty metalworking.
Annotated diagram of the DEWALT DCG400B angle grinder pointing out key performance features including the electronic brake, anti-rotation system, paddle switch, and tool connect chip ready port.
Kit overview for the DEWALT DCG400B bare tool, listing the angle grinder, wrench, Type B guard with Type A clip-on, two Type 1 wheels, and various mounting flanges.
Action shot of the DEWALT ATOMIC 20V MAX angle grinder cutting through a structural steel beam with sparks, demonstrating its lightweight and powerful cordless efficiency.
A professional fabricator using the DEWALT 20V MAX 4-inch cordless angle grinder to grind a steel component, highlighting its design which is 29 percent smaller than standard DEWALT grinders.
Promotional image for the DEWALT DCG400B angle grinder resting on a metal surface, emphasizing the anti-rotation system designed to maximize operator control during binds or stalls.
Close-up action shot of the DEWALT brushless angle grinder in use with a gloved hand, emphasizing the electronic brake designed to stop the wheel in 1.15 seconds for enhanced job site safety.
A professional tradesperson using the DEWALT DCG400B cordless angle grinder to cut a large metal pipe, highlighting that the tool delivers 44 percent more power than 0.7 HP pneumatic grinders.
DEWALT® Product Guides - Grinder Basics promotional how to video
DEWALT

DEWALT Cordless Angle Grinder DCG400B 20V MAX ATOMIC 4 Inch Brushless Tool (755 MWO 12500 RPM Paddle Switch Metal Cutting Weld Grinding Bare Tool)

In stock
SKU: DCG400B
$299.00 USD

Description

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High Velocity Compact Metal Fabrication and Surface Conditioning

The DEWALT DCG400B ATOMIC 20V MAX 4-Inch Angle Grinder is a compact battery-powered metalworking tool engineered to deliver 755 MWO and a 12,500 RPM no-load speed for heavy-duty cutting and grinding. This cordless power tool features an advanced brushless motor that replaces 0.7 HP pneumatic alternatives while reducing overall tool weight to 4.34 pounds for enhanced maneuverability. The system incorporates an integrated electronic safety brake and an anti-rotation mechanism to protect operators from reactionary torque during wheel pinches or stalls in confined spaces.

**Battery and charger sold separately.

Best Used For:

  • Structural Metal Cutting: Slicing through structural steel angles, rebar, threaded rods, and sheet metal panels with high-speed precision.
  • Industrial Weld Grinding: Smoothing heavy weld beads, removing slag, and beveling pipe edges prior to structural joining.
  • Surface Prep Conditioning: Stripping rust, scale, and paint from metal plates using standard wire cups or abrasive flap discs.

Key Performance & Safety Features

  • Anti-Rotation Safety System: Sensors detect aggressive wheel binding or pinching to immediately cut power, minimizing tool twist.
  • Rapid Electronic Brake: Automatic braking assembly forces the abrasive wheel to a complete stop in less than 1.15 seconds upon trigger release.
  • Convertible Guarding System: Includes a Type B grinding guard alongside a tool-free Type A clip-on guard for rapid cutting transitions.
  • Paddle Switch Architecture: Ergonomic paddle trigger integrates a safety lock-off mechanism without a lock-on option to prevent accidental startup.
  • Forward Exhaust Porting: Vent paths route spent internal cooling airflow and structural debris entirely away from the operator's face.

What's Included

  • (1) DCG400 ATOMIC 20V MAX 4-in. Angle Grinder (Bare Tool)
  • (1) Wrench
  • (1) Type B Guard
  • (1) Type A Clip-on Guard
  • (1) 1/16 in. Type 1 Wheel
  • (1) 1/8 in. Type 1 Wheel

Technical Specifications

Tool Power Type Cordless / Battery Powered
Voltage 20V MAX
Motor Type Brushless
Wheel Diameter 4 Inches
Max Speed (No Load) 12,500 RPM
Max Power Output 755 MWO
Switch Type Paddle Switch with Lock-Off
Brake Engagement Time < 1.15 Seconds
Guard Configurations Type A (Cut) & Type B (Grind)
Assembled Weight 4.34 lbs.
Assembled Length 11.8 Inches
Pro-Tip: Always match the guard to the application; use the Type A clip-on guard for abrasive wheel cutoff tasks to redirect flying sparks and fragments away from yourself, and swap to Type B for surface face grinding.