Which impact wrench size to get?

[dwain]

I know all kinds of stuff about Engineering and I couldn't tell you who's right or wrong.

Of course my Engineering knowledge pertains to driving a choo choo train

I would think an identical motor would spin the larger, heavier, anvil, slower thus generating less force, but again, I just blow the whistle and wave at little kids most of the time.

 

hehe. i only mentioned being an engineer to illustrate that a basic knowledge of physics didn't make the previous point clear. designing pipelines etc doesn't help me with this at all

 

if the anvil was the actual load, your point would be very valid . however the force required to make the anvil rotate is insignificant compared to the force required to drive the socket/screw etc.

 

interestingly, if you had two anvils that weighed the same and had the same centre of gravity (the actual difference would be insignificant) but had different size, they would rotate with the same RPM at no load. That is, the outside velocity of the bigger anvil would be higher, but the RPM would be identical. As Dewalt have stated it, both 3/8" and 1/2" 20v compact wrench models have the same RPM (2300).

 

this is all a long way of saying that, IMHO, the motor would determine the torque, and the size of the anvil should have no impact (no pun intended). 

[Conductor562]

Now that makes sense