DEWALT DCG405B Grinder
- Grinder
- 850 watts
- Battery
- 3.8 pounds
- Better rated than 66%
- More reviewed than 88%
A light, 20 volt cordless grinder with 850 watts of motor power, worth considering if you already own DeWalt 20V batteries, since the listing does not confirm one is included.
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How it ranks among the 150 grinders we track
4.7★ across 1,800 Amazon ratings, Bayesian-smoothed toward the category average.
1,800 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
400+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 150 grinders we track - how the scorecard works · full grinders data report. Confidence: high - strong rating volume and complete data.Last refreshed Aug 4, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
The DeWalt DCG405B is a 20 volt battery powered angle grinder rated at 850 watts of motor power and a top speed around 9000 rpm. At 3.8 pounds bare, it is light enough for extended one-handed grinding or cutting work.
DeWalt's 20V MAX cordless platform is the frame this grinder sits in, though the listing does not confirm disc diameter or included accessories, only power figures. Buyers coming from a corded grinder should expect competitive output on paper, with actual runtime depending on the battery pack, which the bare tool style model number DCG405B suggests is not included.
- 20 volt battery powered
- 850 watt motor power
- About 9000 rpm top speed
- 3.8 pound tool weight
Who it's for
Tradespeople already on DeWalt's 20V battery system, who want a light cordless grinder for cutting and light grinding tasks on site, are the target buyer. Anyone needing sustained heavy grinding all day may prefer a corded tool with no runtime limit.
Strengths and trade-offs
Drawn from this product's published specifications.
- Light at 3.8 pounds
- Cordless convenience on the 20V platform
- 850 watt motor output
- Battery and charger not confirmed included
- Disc size not specified in listing
- Cordless runtime limited versus corded tools
Performance notes
850 watts of motor power paired with a roughly 9000 rpm top speed is enough for cutting wheels and light grinding discs. Cordless torque under sustained load will still trail a corded grinder of similar wattage, and runtime depends entirely on the battery pack used.
Specifications
| Brand | DeWalt |
|---|---|
| Model | DCG405B |
| Motor Power | 850 watts |
| Power Source | Battery |
| Item Weight | 3.8 pounds |
| Voltage | 20 volts |
Other DeWalt grinders
How it compares
This product against the closest alternatives we track in grinders.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| DEWALT DCG405B GrinderThis product | 4.7 / 5 | 1,800 | 4.4 / 5 |
| Milwaukee 2880-20 GrinderMILWAUKEE | 4.8 / 5 | 2,400 | 4.5 / 5 |
| AVID MW590 GrinderAVID | 4.5 / 5 | 6,100 | 4.4 / 5 |
| Makita 9557PBX1 GrinderMAKITA | 4.8 / 5 | 3,960 | 4.4 / 5 |
| CRAFTSMAN CMCG400B GrinderCraftsman | 4.7 / 5 | 2,900 | 4.4 / 5 |
Similar grinders from other brands
Questions about the DeWalt DCG405B
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
Does the DeWalt DCG405B include a battery?
The listing does not confirm this. The B suffix on DeWalt bare tool model numbers typically means battery and charger are sold separately.
What is the top speed of the DCG405B grinder?
It is rated at roughly 9000 rpm.
How much does the DCG405B weigh?
3.8 pounds for the bare tool.