eTork Analog Torque Wrench Calibration Cert.

[BMWTurboDzl]

I picked up an analog wrench because I'm going to replace some pulleys along with the serpentine belt on my 4-series.

This wrench is capable of applying torque in both clockwise and counter-clockwise direction. I was pleasantly surprised to see that my wrench was calibrated at +/- 2 percent in CW and less than +/- 3 percent in CCW. The accuracy of the calibration equipment is +/- .5 percent.

I think that's pretty good for a $55 "clicker".


The adjustment knob is so ridiculously easy to use and read.

 

[doitmyself]

While the accuracy of the torque wrench is important, keep in mind that all of the possible variables associated with the process amounts to an uncertainty of about +/- 25%.

https://www.surebolt.com/torque_errors.htm

What interests me is that the owner of etork came from JS Technology in Georgia, the U.S. manufacturer that used to make torque wrenches labeled for Craftsman, KD/Gearwrench, NAPA, Armstrong, MATCO, some SK, and others. https://etork.com/about/ . If his expertise comes with the etork wrenches, they might be better than other run-of-the-mill Chinese ones.

EDIT for atikovi: you can find the same figures in many engineering articles. My intent is to remind people that a 1 or 2 percent difference between different torque wrench brands is moot because the entire torque measurement process (by turning) is very crude. Too many people think that using a sophisticated tool guarantees an accurate outcome. An unskilled shooter would not do much different with a $400 Mossberg shotgun vs. a vintage $3,000 Browning.

 

[atikovi]

While the accuracy of the torque wrench is important, keep in mind that all of the possible variables associated with the process amounts to an uncertainty of about +/- 25%.

https://www.surebolt.com/torque_errors.htm

What interests me is that the owner of etork came from JS Technology in Georgia, the U.S. manufacturer that used to make torque wrenches labeled for Craftsman, K&D, NAPA, Armstrong, some SK, and others. https://etork.com/about/

Says the company hawking a $20,000 bolt tensioning gauge thing.

 

[BMWTurboDzl]

While the accuracy of the torque wrench is important, keep in mind that all of the possible variables associated with the process amounts to an uncertainty of about +/- 25%.

https://www.surebolt.com/torque_errors.htm

What interests me is that the owner of etork came from JS Technology in Georgia, the U.S. manufacturer that used to make torque wrenches labeled for Craftsman, KD/Gearwrench, NAPA, Armstrong, MATCO, some SK, and others. https://etork.com/about/ . If his expertise comes with the etork wrenches, they might be better than other run-of-the-mill Chinese ones.

Just a fyi.. That 25% figure is the variance in "tension" among a group of bolts holding a flange together. Not exactly relevant to the application.

 

[doitmyself]

I don't agree BMWTurboDzi. I think that the article(s) are saying that in a flange type connection, tension may vary even more, up to 50% between each one.


"Identical bolts, when tightened to identical torque values, will vary substantially in their actual tensions (typically plus or minus 25%, and not uncommonly plus or minus 50% on flanges). Why?" https://www.surebolt.com/surebolt.htm

My assertion still applies. No matter that the wrench has an accuracy of about +/- 3%, the variables of the entire process can result is tensions that are +/- 25%. For our use, i.e. engine heads, this is good enough.

 

[BMWTurboDzl]

I don't agree BMWTurboDzi. I think that the article(s) are saying that in a flange type connection, tension may vary even more, up to 50% between each one.


"Identical bolts, when tightened to identical torque values, will vary substantially in their actual tensions (typically plus or minus 25%, and not uncommonly plus or minus 50% on flanges). Why?" https://www.surebolt.com/surebolt.htm

My assertion still applies. No matter that the wrench has an accuracy of about +/- 3%, the variables of the entire process can result is tensions that are +/- 25%. For our use, i.e. engine heads, this is good enough.

Correct. Which as you said is not really relevant for automotive applications.

Oh and btw.. eTork is owned by Jan S Stasiek who founded JS Technology.

 

[doitmyself]

We could argue for 5 more pages like the distilled water for coolant thread, LOL. Even if you are correct, I am usually more correct (what I tell my wife!) Plus, I am 65, so correctness does not even matter.




Let us know how that wrench works out, as I am interested in them. Shameless plug for Jan: https://etork.com/

 

[Trav]

I picked up an analog wrench because I'm going to replace some pulleys along with the serpentine belt on my 4-series.

This wrench is capable of applying torque in both clockwise and counter-clockwise direction. I was pleasantly surprised to see that my wrench was calibrated at +/- 2 percent in CW and less than +/- 3 percent in CCW. The accuracy of the calibration equipment is +/- .5 percent.

I think that's pretty good for a $55 "clicker".


The adjustment knob is so ridiculously easy to use and read.

These are a Norbar clone, the quality isn't the same but neither is the price. Overall for occasional use they are a good tool.

 

[doitmyself]

Thanks Trav.. Wow, their electronic torque wrenches are really priced low also. I wish we could entice the mfg. to share what their build quality is like. Remember, not that I like the situation, but the Chinese are already building most of our quality electronic gadgets - Iphones, computers, etc..

 

[Trav]

Yes their electronics are low priced and decent enough but they are not full featured, not as accurate as more expensive ones and generally not repairable out of warranty for less than their cost new. That being said for DIY use where a non angle tool is needed they seem to be more than good enough according to the people that have them.

 

[DougR]

I check calibration on torque wrenches even if relatively new. The newest "clicker" I have is 7% off. The oldest "clicker" is 11% off. Two 45+ year old beam style torque wrenches are out of calibration by 5%.