Dewalt DW057 vs DW056 torque output

[gtstcactus]

I have both the DW057 & DW056 impacts...

The DW057 is 1/2 inch square impact wrench, the DW056 is 1/4 inch hex impact driver.

The DW057 outputs 138 ft/lbs according to Dewalt, the DW056 outputs 98 ft/lbs according to Dewalt. How is that possible given that they use the same motor, the same impact mechanism, and same trigger...???? There doesn't seem to be any other parts which would affect torque output unless the size of the driver explains the difference...

Does a 1/2 inch square drive out put more torque than a 1/4 inch hex drive when all else is the same??

 

[bsaint]

They may limit the current on the smaller one

 

[MattPSC]

Weight of the anvil adds to the torque.

 

[gtstcactus]

Weight of the anvil adds to the torque.

That makes sense given it is the only differing part between the 2...

I find it surprising that the anvil of the DW057 is responsible for an extra 40 ft/lbs of torque but I guess there is really nothing else that could explain it...

I don't think there is any current limiting in the DW056 to reduce torque. The 2 tools are virtually identical from the battery through to the motor. They differ at the anvil / driver area only.

 

[LordPsychon]

The anvil weight is what gives it more "oomph" - force equals mass times acceleration so more mass and equal acceleration gives you more force.

 

[bsaint]

Yea ever see weighted sockets? The relatively small amount of extra mass around the outside makes a world of difference.