A Torque Wrench to Adjustable Wrench Adapter

[rgsparber]

There are times when I sure could use an adjustable wrench that indicates torque. Well, I've got an adjustable wrench and I've got a torque wrench. Why not just stick them together? Does this change the amount of torque being applied?

If you are interested, please see

https://rick.sparber.org/TorqueWrenchAdapter.pdf


Your comments are welcome. All of us are smarter than any one of us.

Thanks,

Rick

[DIYer]

Thanks rgsparber! We've added your Torque Wrench Adaptor to our Fastening category,
as well as to your builder page: rgsparber's Homemade Tools. Your receipt:

Torque Wrench Adaptor by rgsparber

tags: wrench, torque, adaptor

[rebuilder1954]

Rick, I confess this is stripping my gears. I don't have a beam deflector style torque wrench, only the clicker style. to boot, i am 250 miles from home and unable to construct a test for a few more days. but in my mind, i am visualizing a 100 lb weight on the end of the wrench, and adjusting it to barely trigger the click. and then trying the same 100 lb weight 6" closer to the square drive. i'm thinking it would not click. am I misunderstanding your concept?

i love the idea of tying non-square drive connections to the square drive of my torque wrench, to measure the applied torque. but your engineering-trained brain has me beaten on this one.

thanks for stretching the grey matter, sir.

[rgsparber]

Rick, I confess this is stripping my gears. I don't have a beam deflector style torque wrench, only the clicker style. to boot, i am 250 miles from home and unable to construct a test for a few more days. but in my mind, i am visualizing a 100 lb weight on the end of the wrench, and adjusting it to barely trigger the click. and then trying the same 100 lb weight 6" closer to the square drive. i'm thinking it would not click. am I misunderstanding your concept?

i love the idea of tying non-square drive connections to the square drive of my torque wrench, to measure the applied torque. but your engineering-trained brain has me beaten on this one.

thanks for stretching the grey matter, sir.

I did screw up. Standby for an update that will include a correction factor.

Rick

[Murph1090]

You mount your attachment 90 degrees from the beam, and no correction factor is needed, just like a crow's foot.

[Gadgeteer]

You mount your attachment 90 degrees from the beam, and no correction factor is needed, just like a crow's foot.

I think you still need to consider that in your postulated configuration the torque would, actually, be considered to be applied along the hypotenuse length between the torque wrench handle and the end of the added wrench sitting on the bolt/nut to which the torque is applied. So, the applied torque would be a bit more than what is read on the torque wrench scale, since the cord length is longer than the torque wrench.

[Gadgeteer]

What you've accomplished, Rick, is a torque wrench extender. I had to make one a few decades ago, so I could torque the nut on a VW drive shaft to 300# with my 150# torque wrench. I made a simple extension, which doubled the length of the torque wrench. So, I achieved the 300# when the scale on the wrench read 150#.

The formula for figuring out applied torque by adding additional lengths of adapters is found here:

[rgsparber]

You mount your attachment 90 degrees from the beam, and no correction factor is needed, just like a crow's foot.

According to

Torque Wrench Adapter Formulas

what you say is true provided the adjustable wrench is less than 2-inches long. I think they are saying that keeping under 2-inches makes the error small enough to ignore for their application.

When i tried it, I did see a difference compared to using a socket: 95 inch-pounds using just the socket versus 70 inch-pounds with my 6.3-inch long adjustable wrench set at 90° from the major axis of the torque wrench. This was the same reading as with the adjustable wrench aligned to the major axis. I think I understand what is going on with the two wrenches in alignment but I'm still confused that being at 90° gives the same reading. I thought the distance would be a straight line from the pivot pin inside the handle to the bolt head. But that gives me a result that is inconsistent with the torque readings.

I'm still learning...

Rick

[katy]

Here ya go. IIRC this came from Busted Knuckles magazine.

[rgsparber]

Here ya go. IIRC this came from Busted Knuckles magazine.

Katy,

I see a large offset between the fat bar on the torque wrench and the major axis of the extension wrench. This will cause a twisting force which I'm trying to avoid by lining them up. I have seen the equation on two web sites plus plugged in my own numbers and got consistent results.

Thanks,

Rick