Air tool CFM chart
Consumption at 90 PSI, with the duty cycle that decides what the compressor has to sustain. Nameplate CFM alone tells you almost nothing about what machine you need.
| Tool | CFM at rated PSI | PSI | Duty cycle | Sustained | Use |
|---|---|---|---|---|---|
| Impact wrench, 1/2 in | 4.5 | 90 | 20% | 0.9 | Intermittent |
| Impact wrench, 3/8 in | 3.5 | 90 | 20% | 0.7 | Intermittent |
| Air ratchet, 3/8 in | 3.0 | 90 | 25% | 0.8 | Intermittent |
| Die grinder | 5.0 | 90 | 60% | 5.0 | Continuous |
| Cut-off tool | 4.0 | 90 | 50% | 4.0 | Continuous |
| Random orbital sander | 6.0 | 90 | 90% | 6.0 | Continuous |
| Dual action sander | 11.0 | 90 | 90% | 11.0 | Continuous |
| HVLP spray gun | 9.0 | 40 | 70% | 9.0 | Continuous |
| Blow gun | 3.0 | 90 | 10% | 0.3 | Intermittent |
| Brad nailer | 0.3 | 90 | 5% | 0.0 | Intermittent |
| Framing nailer | 2.2 | 100 | 5% | 0.1 | Intermittent |
| Tyre inflator | 2.0 | 90 | 15% | 0.3 | Intermittent |
| Air hammer | 4.0 | 90 | 30% | 1.2 | Intermittent |
| Sandblaster, small | 12.0 | 90 | 90% | 12.0 | Continuous |
Sustained demand for an intermittent tool is nameplate times duty cycle. For a continuous tool it is the full nameplate figure, because there is no idle time for the tank to recover in.
Compressor needed for each tool on its own
Including the standard 30 percent margin.
| Tool | Required SCFM | Compressor |
|---|---|---|
| Impact wrench, 1/2 in | 1.2 | 2.6 SCFM |
| Impact wrench, 3/8 in | 0.9 | 2.6 SCFM |
| Air ratchet, 3/8 in | 1.0 | 2.6 SCFM |
| Die grinder | 6.5 | 7.8 SCFM |
| Cut-off tool | 5.2 | 6.4 SCFM |
| Random orbital sander | 7.8 | 10.5 SCFM |
| Dual action sander | 14.3 | 17.5 SCFM |
| HVLP spray gun | 11.7 | 14 SCFM |
| Blow gun | 0.4 | 2.6 SCFM |
| Brad nailer | 0.0 | 2.6 SCFM |
| Framing nailer | 0.1 | 2.6 SCFM |
| Tyre inflator | 0.4 | 2.6 SCFM |
| Air hammer | 1.6 | 2.6 SCFM |
| Sandblaster, small | 15.6 | 17.5 SCFM |
Read your own tool's plate
These are class averages and individual tools vary a great deal. Manufacturers also publish consumption differently: some quote average use, some continuous, and a few quote the figure at a pressure other than 90 PSI. Where it matters, the number on your tool wins over the number here.
Frequently asked questions
How much CFM does an impact wrench use?
A 1/2 inch impact wrench draws about 4.5 CFM at 90 PSI while it is running, but it runs in short bursts, roughly 20 percent of the time. Sustained demand is closer to 0.9 CFM.
How much CFM does a sander need?
A random orbital sander takes about 6 CFM and a dual action sander about 11 CFM, and both run continuously, so the compressor must supply the full figure rather than an average. This is the tool that sizes most workshop compressors.
What does duty cycle mean for air tools?
The fraction of the time the tool is actually consuming air. A nailer fires and stops, so its duty cycle is a few percent. A sander runs the whole time it is in your hand. Two tools with the same nameplate CFM can need completely different compressors because of it.