Impact Driver of max 120 Nm won't undo 90Nm wheel bolt

[Sensibleboy]

Just bought a Erbauer impact driver with a max torque of 120Nm.

It won't undo a wheel bolt torqued to 90Nm. The clutch slips. It's not the motor that's too weedy.

I'm probably overlooking something but it doesn't seem right to me.

I can beat the clutch if I hold the socket in my hand. Does this sound normal?

My torque wrench set to 50Nm managed to undo the bolt that was tightened by the impact driver.

Edited by Sensibleboy on Saturday 8th September 11:29

[Sensibleboy]

It's an 18V model.

I suspected the break off requirement might be the issue.
I might take it back to the shop. I'll see if a replacement has the same characteristics.

I only got it to speed up assembly but it does seem a bit pathetic if it can only manage 50Nm.

Edited by Sensibleboy on Saturday 8th September 13:13

[Sensibleboy]

I didn't get it specifically for wheel bolts I just thought I'd see what it could do.

What's the 120Nm all about then if it can only actually tighten something to 50Nm?

[Sensibleboy]

I bought it simply to save some time and effort. Putting an engine and suspension back in a car needs a lot of spanner work.

So should I expect an advertised 120Nm that only tightens to 50Nm to be reasonable?

I've got an impact wrench already and every other breaker bar, torque wrench etc so all that was missing was the impact driver.