To put these results in perspective, we tried pulling the wrench to failure — the much lower ~50 ft-lb failure point after we initially over-torqued it — by hand. It was pretty darn difficult and required a good bit of pulling with both hands.
In short: You’re going to have a tough time exerting 225 ft-lbs of torque on a 8″ lever. Truthfully, you’re going to have a tough time exerting 100 ft lbs of torque without sliding something over the end of the wrench.
Curiosity Overwhelms Us
Having flexed the case of our little AutoWrench too much for it to be useful, we couldn’t resist taking it apart and looking around inside. It’s actually pretty cool.
A small DC electric motor drives the screw via an itty-bitty belt. From what we could tell, the wrench’s “clutch” functionality is provided by the low torque of the motor itself as opposed to any complex mechanism.
The battery box, motor, and switch can be easily removed for use in other projects, so if you do happen to break your AutoWrench, don’t pitch it. Chances are good you “over-flexed” the metal casing rather than destroying the motor or belt.
The AutoWrench is a handy tool. Our tests proved that it can hold up to just about any realistic use around the house or home shop — or for that matter pretty much any shop. One reliability note: if you do manage to over-torque the wrench, it’ll never be the same again. Granted, you’ll probably need to either jump up and down on it or stick a long pipe on it to over-torque it, but we’ve certainly seen stranger things happen.
We only see one drawback to the AutoWrench, and that’s battery cost. If you only use it rarely, its two AAA batteries would last quite some time. But if you’re not using it much, do you really need the automation?
If you commonly use an adjustable wrench while hanging on to something else — or you just love cool gadgets — the AutoWrench will help. It’s not as strong as a standard adjustable wrench, but then again neither are you.
Street pricing starts around $30.