Torque wrench test! (Proof that hand position REALLY matters.) | Auto Expert John Cadogan

I learned many years ago not to be dogmatic or disrespectful in my approach because it makes a further trip down Backpedal Road when you've been proven wrong. Good practical demonstration proving the twin pivot explanation.

I have used torque wrenches for more than 30 years in engine assembly, wheel fitting etc. and always just used it as per manufacturer's recommendation, so it was interesting to see how NOT following the prescribed method for use completely messes up the actual torque.

Being a mechanic from years ago in England,, that's the way we used them, the hand grip is there for a good reason.

Had never thought about the relationship of the hand to torque, but makes sense when explained! Thanks for the video.

Here's a thought experiment that might help any doubters: imagine taking it to the extreme, applying the force at the pivot point of the clicking mechanism (the elbow, if you will). You'd never get it to click, no matter how hard you pull. Yes, it would be harder to achieve a given torque, but the tool's torque limit would basically be infinite.

Lovely practical test, that proves all the things discussed in the previous parts. Thanks for putting this online, now I can have a place to send people to when they disagree with the reality about this issue.

As an armchair science guy, I've learned never to argue with actual science guys. They know their sh!t, like it or not. Love your work.

I think that's called walking the walk and talking the torque.

Once upon a time in a world long ago teaching the correct way to use small tools was a real thing...gone now. I appreciate the time and effort you put into explaining the dos and don'ts of using tools.

When you explained that the relationship between the distance from the fastener to the hand and the pin to the hand changes, it all made sense. I would never have assume this was the case, though it seems obvious now. Thanks for sharing.

"Wrenchgate" I love it. Nice work John.

Before anyone starts about those digital torque adapters, i worked for a test lab and tested at a number of them and they are not only accurate but consistent, just don’t football them across the floor

well, well, well, against all my reasoning the results do change. good thing i watched. Thanks JC.

I’m quite looking forward to the 5 part mini series on how to use a shifter. Thanks John.

I love the way you speak to your critics. If they don’t listen properly or read for themselves, perhaps you’ll have to get a whiteboard and draw them pictures.

As it has been said: the only real laws are the laws of physics, the other laws are recommendations. Great job, John.

Would have loved to see an extension tube used to demonstrate fully the principle.

I just went through the physics calculations for fun. It was interesting to see the error magnitude variance based on not only the ratio of socket center vs. pivot point but as well as the ratio of the inner bearing snap point to the force applied at the handle distance. My rough assumptions for choking up to 1/2 shaft distance (and taking apart one of my torque wrenches for measurement) provide error calculation between the errors you measured with the two wrenches.

Gday John, I glad you showed this demonstration, I’ve looked at a lot of the comments in the past videos and was blown away, you don’t put false misleading information out there, as you said it’s your credibility at stake, top job mate, cheers

I slept on it for a day and in the morning: Okay, I think I got it. Due to the design of the tool, the torque is measured on a different force arm than when the torque is applied to the screw. The ratio of these force levers is a given value when holding the grip, and the tool is calibrated for this. If you hold it somewhere other than the grip, the ratio of the power levers changes, and the torque exerted on the screw also changes when it is clicked. I admit, I was wrong, but it's a catchy topic, I studied mechanics a long time ago, but I always wanted to understand things, I didn't believe it until then :)