# Help with Impact and Ratchet Air Wrench Comparison, Confusing Specs don’t match



## caliskier (Mar 14, 2009)

I am trying to compare two tools: Kobalt Impact Wrench and Craftsman Impact Wrench. I need help understanding why one is better over the other.

Kobalt ..............................................................................Craftsman
Air Pressure 90psi ............................................................Max Air Pressure 90psi
Ave Air consumption 4 CFM ............................................Ave Air Consumption 4.4 SCFM
Max Torque 360 ft. lbs .....................................................Max Torque 300 ft lbs
Free speed 7000 rpm +/- 10%.......................................... Free Speed 7500 rpm

Frustrating thing is one is measured in CFM and the other is SCFM. Max torque tells me to go with the Kobalt but the Ave Air Consumption on the Craftsman is higher, but again the units aren’t the same CFM vs SCFM

The other tool is the Ratchet Air Wrench

Kobalt ...............................................................................Craftsman
Air Pressure 90psi ..............................................................Max Air Pressure 90psi
Ave Air consumption 3.5 CFM ...........................................Ave Air Consumption 4.9 SCFM
Max Torque 60 ft. lbs .........................................................Max Torque 45 ft lbs
Free speed 160 rpm +/- 10%.............................................. Free Speed 150 rpm

Here again torque much better on Kobalt but Ave Air Consumption on the Craftsman is higher, was thinking that ave air consumption meant it was more powerful. Don’t know, very confused. Please help.


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## Maintenance 6 (Feb 26, 2008)

For your purposes SCFM and CFM would mean the same thing. Everything else being relatively equal, I would go with the higher torque models.


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## caliskier (Mar 14, 2009)

Maintenance 6 said:


> For your purposes SCFM and CFM would mean the same thing. Everything else being relatively equal, I would go with the higher torque models.


Thanks so the ones with the higher SCFM do not necessarily mean better performance?


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## ponch37300 (Nov 27, 2007)

CFM is the measurement of air it takes to make the torque. One tool might be more efficient so it creates more torque with less air consumption. Kinda like saying one car can go farther than another on less gas.


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## caliskier (Mar 14, 2009)

ponch37300 said:


> CFM is the measurement of air it takes to make the torque. One tool might be more efficient so it creates more torque with less air consumption. Kinda like saying one car can go farther than another on less gas.


Thanks guys, air tools are very confusing


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## JayL (Jun 8, 2008)

You want to get air tool experts then visit

www.garagejournal.com :thumbsup:


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