If I put a snap on crows foot attachment on the end of a torque wrench will it throw off the readings. I have come across torque specs for fittings on hydraulic lines and such.
yes. But it can be accounted for. https://www.fordservicecontent.com/renderers/torquewrench/wrench_formula_en.asp?type=180degcrow
I've always wondered how far off the torque would be with a long extension between the torque wrench and the socket. Must be a formula for that, as well.
Not sure there is a formula as much as measuring. That's how those torque sticks worked. They were varying thickness and would 'flex' less or more when used with an impact. https://thegrumpymechanic.com/how-do-torque-sticks-work/ So I'd guess without testing that it's a percentage, and that it varies depending on the extension.
If the crows foot is 90 degrees the torque wrench will read normal. Found this online , shows what is going on better than I can explain. Hope this helps. Dan
The above diagram is probably not exactly correct because L would be a little longer than shown as I believe L should be measured from the center of the wrench as well as center of the handle but the results are more than likely well within the torque wrenches accuracy range and well within the tolerance needs for our work. Dan
An extension between the socket and torque wrench does not change the reading. Torque is rotational force. Torque sticks are only supposed to be used with an impact.
I have often used an extension when torquing stuff. It gets your knuckles up and away from the part. If at all possible, I will use that same setup to do all the fasteners in cases like head bolts. I have always used the strongest extension I could and used the torque spec laid out. My feeling is that even if it's off due to the extension (or not), the main point is to get it close and even. If you are concerned with the change using an extension, the wrench better be certified by a machine that has been recently calibrated, too. And the threads and shoulder better be clean and lubed exactly. A torsion bar shows that application of force at one end doesn't transfer perfectly to the other, but unless you are using a 1/4 inch drive to torque triple digit numbers, it should be negligible.
Using an extension shouldn’t affect the torque it’s static 100 lb ft at the wrench will be 100 lb ft at the fastener even if the extension twist some and it will twist. Dan
As an aircraft mechanic, this is part of the training. The diagram up top is correct, and yeah, it’s a bit of a pain to calculate. However, as also stated up above, placing a crow’s foot at 90 degrees will not impact the torque reading. Socket extensions do not affect torque readings unless they’re real ****ty extensions with a whole lot of twist. If you’re using a high-quality extension, the bolt will give before you twist the extension, ***uming it’s properly sized that is. I wouldn’t be using a 1/4 extension to torque a 1/2 diameter bolt.
What changes with an extension is how much farther around you have to move the torque wrench before the bolt moves, ***uming the extension twists.
Yes that is what I was trying to say, the extension , any extension is going to twist some, how much is determined by the force and the strength of the extension but really doesn’t matter because the force will be transferred to the fastener. Dan
I was taught when using an extension, to keep it at 90 degrees to the bolt/nut. I can’t recall why, but just remember that tidbit. Heck, I don’t even like using a deep socket on a torque wrench.
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