Do torque wrenches have adaptors?

[Sean Perkins]

I’m looking to get a torque wrench. If I got a 1/2″, are there adaptors to use with my 3/8″ sockets?
Thanks

Topic

[richiepearce]

yes readily available

[Paul]

You can use a standard 3/8″ to 1/2″ adapter with a torque wrench, although it might cause an error with a torque-angle measurement.

[richiepearce]

have a look here http://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm
to work out the torque settings for using extensions and adaptors

[Its me]

The link above shows if you change the distance of the fastener to the torque wrench head, I.E. Torque adapter..

This is a torque adapter..

There is so much bad stuff out there about using an extension on a torque wrench that a few months ago I wrote the following post…

SIMPLY STATED, using a socket extension or size adapter (1/2″ to 3/8″) perpendicular to the head of the torque wrench DOES NOT change any torque values… PERIOD… It is fine to use an socket extension or drive size adapter…

____________________________________________________________________________________________________

MY POST:

I will respectfully disagree about the “bad” effect of socket extensions on a torque wrench and do not wish to start an argument, but to point out some facts…. This topic has been something that has been discussed for years. I have discussed this with a physicist and a mechanical engineer…. However I will link a few articles that explain it better than they and I can…

While I do believe in practice about limiting the length of an extension when using a torque wrench and I also agree about not using multiple extensions if at all possible, it is only for the sheer reason of the possibility of being off of the proper 90 degrees of the torque wrench head to the applied fastener. As if the extension would make a wobble extension kind of effect.

Simply stated, when the torque is applied and even loose ends in extensions are at their corners and the torque is evenly applied at 90 degrees to the fastener, then no torque is lost (as long as the torque is applied evenly and smoothly and the extensions are not jarred)… the effect of any type of twisting of the metal in the form of heat as lost energy it is so negligible it is not a even a factor…. If ones imagination went so far, they could postulate how an deep impact socket could “twist” more than a standard impact and less so for a chrome than a deep chrome, but it is still looking WAY too deep…

Quite simply a short 1/2 to 3/8 extension would have zero, absolutely no discernible effect on torque measurement and should cause you no concern…

After all most torque wrenches have a 2-4% margin of error… So have no fear of using an extension, especially one as short as an adaptor…

Here is more info..

Note the second link has a formula for computing torque change with a HORIZONTAL extension (meaning making the torque wrench longer)… Note without that horizontal extension the formula is the same… there is no formula for adding a length of depth extension… It is simply the same formula without ‘B’ which is the same as applied torque…

The third link has A&P (aircraft) mechanics discussing how torque is not lost through extensions…Including one who mentions using 8 foot extensions on some jobs… Another aircraft mechanic goes so far as to point out Newtons third law (hmmm… Newton meters): For every action, there is an equal and opposite reaction. Meaning that even if there is a twisting of the perpendicular extension (as so many are concerned about)… Then where does this twist go? Well if it was a torque stick it would bounce back, but the energy can only go one place left… Heat… and that is not even in the equation… My only conciliation here is if there is a slight spring back when the torque wrench is released (which has happened on occasion to me with an extension and without one)….. that is a loss of some torque… but can be re-checked if one is so concerned… and remember the plus or minus 2-4% accuracy on any bolt… So you may be off a ft-lb or two and never know it…

This is a good quote – “torque is calculated as a force multiplied by a distance. where distance is defined as the PERPENDICULAR distance from the point you are acting. the length of the extension never comes into the equation. and if this was an important thing to consider when torquing critical fasteners, you would find all kinds of literature about it. The inconsistencies of threads on the fastener and the machined hole will have a much greater influence on the torque readings you “measure” vs. the “actual” torque.”

This is one of the best ways to put it about deflection (not mine) – “If you apply torque to one end of a solid shaft, that torque will be transmitted without loss to the other end. This is because there is no counter-acting force or torque applied anywhere along the shaft (eg, no friction).
The longer the shaft, the more rotational deflection of the shaft will occur, but the torque wrench is impervious to that deflection because it does not use the deflection of the extension shaft to determine torque. It measures the torque that it applies to its square drive.”

Point is, engineers have formulas for everything… Why not one when you add a 4 inch, or a 6 inch, or 10 inch socket extension??? (see page 5 of the snap on techangle link for all the different formulas)… Funny how adding a perpendicular extension is not listed and even a 15 degree wobble extension is within acceptable use…

Good reads:

http://www.f150online.com/forums/articles-how-t…ches-extensions.html

http://www.torqwrench.com/Info/FAQ.html

forums.corral.net/forums/5-0-5-8-engine-…n-torque-wrench.html

buy1.snapon.com/products/torque/pdf/tech…0INTERNET%20SITE.pdf

-Karl

[richiepearce]

I agree Karl the reason i posted the link is to make people who may have to use adapters such as crows feet aware of change in torque values etc…

[Author]

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