Astro 204 ONYX 90 Degree Angle Die Grinder 1/4 Inch
- Power Source: Pneumatic
- Material Type: Composite
- Item Weight: 1.2 pounds
- Color: Green,red
Last refreshed Aug 4, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A pneumatic detail grinder that only makes sense if you already have a compressor feeding your air line.
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ASIN: B0083RPU8EModel: 204Category: Power Grinders
Overview
The Astro 204 is a pneumatic grinder, meaning it runs off a compressed air line rather than a battery or cord. At 1.2 pounds it is light enough for one-handed detail grinding work.
Astro Pneumatic built its catalog around air-powered shop tools, and the 204's power source confirms it belongs to that category rather than the electric grinder segment some buyers might expect from the plain title. Anyone shopping this listing needs an air compressor and hose already in place, since the tool itself will not run without one.
- Brand: Astro
- Model: 204
- Category: Grinders
- Power source: pneumatic
Who it's for
Best for shops and garages that already run a compressor and want a light pneumatic grinder for detail or die-grinding work. Not a fit for anyone without compressed air on hand, or looking for a cordless electric option.
Pros and cons
- Light at 1.2 pounds for one-handed use
- Pneumatic power avoids battery weight
- Requires a compressor and air line to run
- No further specs on collet size or RPM
Performance notes
Pneumatic grinders draw power from a shop compressor through an air hose, which typically gives them a higher power-to-weight ratio than a similarly sized electric grinder. At 1.2 pounds the 204 is built for maneuvering into tight spots rather than for heavy stock removal.
Specifications
| Brand | Astro |
|---|---|
| Model | 204 |
| Dimensions & fit | |
| Item Weight | 1.2 poundslower than 76% of 107 power grinders |
| Power & efficiency | |
| Power Source | Pneumatic |
| Construction & materials | |
| Material Type | Composite |
| Color | Green,red |
| Included components | |
| Unit Count | 1 |
| Included Components | Funnel |
| Other details | |
| Style Name | Compact |
Closest rivals on specs
Frequently asked questions
Does the Astro 204 need a compressor?
Yes, it is pneumatic-powered, so it runs off a compressed air line rather than a battery or cord.
How much does the Astro 204 weigh?
It is listed at 1.2 pounds.
Is the Astro 204 cordless?
No, it is an air tool, not a battery or corded electric grinder.