Checking a Torque Wrench

[Kiwi_Roy]

I know there are probably many firms out there that will check the accuracy of a torque wrench;

Give us a few cheap and dirty ways to check them at home,
The obvious way is against a known weight on a lever but if you don't have that, then what.

I ask because I have 2 reading quite a bit different, like 30%

[rodekyll]

I know there are probably many firms out there that will check the accuracy of a torque wrench;

Give us a few cheap and dirty ways to check them at home,
The obvious way is against a known weight on a lever but if you don't have that, then what.

I ask because I have 2 reading quite a bit different, like 30%

We used to get one guy in the shop to pay for his calibration and then we'd hook his wrench up to ours and see if they clicked at the same time.  If they needed adjusting we'd buy his beer.

[Sasquatch Jim]

  I have a square hole socket that allows me to mate up my pointer indicater wrench with my click type wrench.
  Grab the handles firmly and torque ad read the needle when the other clicks.

 BTW, with click types you should return the vernier to zero after use.

[Chuck in Indiana]

 I have a square hole socket that allows me to mate up my pointer indicater wrench with my click type wrench.
  Grab the handles firmly and torque ad read the needle when the other clicks.

 BTW, with click types you should return the vernier to zero after use.

 :+1

[acogoff]

     I use a somewhat accurate fish weight scale. Hook a strong cord 12 inches out from the centerline of you socket and pull with the fish scale. With some simple math you can figure what the scale should read as the torque wrench clicks. You can use a section of pipe around the handle and get say 3 feet away from the centerline for the higher settings. Using the 3 ft. set up applying 20 Lbs 3 ft away gets you 60 ftlbs at the nut you are doing up. The same principle applies be it Ft lbs or inch lbs, just use some math. Just use a vise to hold the square bit of your wrench while calibrating.

[Wayne Orwig]

Glad I use bending beam torque wrenches. If it is zeroed, it is calibrated.
 :BEER:

[sib]

Here's my never-fail method:  use the wrench to tighten up an oil drain bolt.  If the threads in the oilpan strip, you know the wrench is out of adjustment.

[normzone]

I manage a collection of tools that my employer gets calibrated once a year for ISO 9001 purposes. The calibration house charges $30 to do a torque wrench.

My veteran mechanic buddy says the difference in readings between a pricey torque wrench and a Harbor Freight special can run 10%.

[Rough Edge racing]

Glad I use bending beam torque wrenches. If it is zeroed, it is calibrated.
 :BEER:

 I use a bending beam for some stuff. But sometimes the position you must work in prevents getting a look at the scale.. . And there's been a few recent videos  here of so called expert bike builders you use a torque wrench incorrectly.

[garbln]

I manage a collection of tools that my employer gets calibrated once a year for ISO 9001 purposes. The calibration house charges $30 to do a torque wrench.

My veteran mechanic buddy says the difference in readings between a pricey torque wrench and a Harbor Freight special can run 10%.

I ran the Cal lab at a large Mfg plant for a number of years, and torque wrenches were one of the things we maintained in house.  Checking them out once in a while is a good idea, but some things to keep in mind are.  The low end of the range on a given wrench has the poorest accuracy, try not to use the bottom 25-30% of the range, some are better but this is a good rule of thumb.  Exercise the wrench before use, meaning if you plan to to torque to 30 ft lbs, torque a dummy nut or bolt to that torque first than do the the real thing.  The difference in applied torque between two people using the same torque wrench can be significant 10-20% at times.  All people using torque wrenches at our plant were given a training session on how to use a wrench properly.  A strait smooth pull with as few extensions as possible is best.  Just try to use the wrench with the same smooth pull every time and you will do fine.

[Stevex]

Working in an aircraft maintenance hangar I'm lucky enough to have access to calibrated torque wrench checking equipment.
Not only can I check how accurate my wrench is but as I can see the torque read out rise as I apply force, it's amazing to see how easy it is to get, what everyone thinks is a highly accurate method, so wrong. As said above, smooth, consistent applied force is the way to accurately torque up fasteners.

[LaGrasta]

http://www.wikihow.com/Calibrate-a-Torque-Wrench

[normzone]

Interesting that training should be so important. Duh, I pester people about that on a regular basis, I should have suspected.

That's the problem when a process looks like a no-brainer - it's not necessarily so.

[cloudbase]

https://youtu.be/jdVR6T0cxXg

[Kiwi_Roy]

Some interesting response, I think I like the fish scale method the best, nice and compact. The scale can also be used with a regular wrench where the torque wrench won't fit.
A luggage scale might work too

Wayne, I assume you have a beam scale with the little pop out pin, my simple pointer one is next to useless.


Shirley I'm not the only one who finds torque figures stated in Foot Pounds instead of Pounds Feet annoying, even the torque wrench has it backwards

[ridingron]

Shirley I'm not the only one who finds torque figures stated in Foot Pounds instead of Pounds Feet annoying, even the torque wrench has it backwards

OK, I'll bite. Why do you prefer pound feet as opposed to foot pounds. Wrong word plural?

[rodekyll]

Pounds Feet sounds like a tribal name for a clog dancer.  Mine is Runs-With-Scissors.

[lucian]

I usually fart when mine hits 120 ft lbs. Close enough  :BEER:

[Larry_77084]

https://youtu.be/jdVR6T0cxXg

Now that's the way to do it.
 

[Semper-guzzi]

Now that's the way to do it.

Holy jeez that was funny. Blue electrical tape. Black epoxy tape. Hot glue Bic pen. That had me going. He cut titanium with a Swiss army knife scissor. I'm still rolling. Wow. Awesome.

[Wayne Orwig]

Wayne, I assume you have a beam scale with the little pop out pin, my simple pointer one is next to useless.

Just a normal beam scale. Couple of them actually. I did add some manual markings the underside so they are usefully when inverted.

[Kiwi_Roy]

OK, I'll bite. Why do you prefer pound feet as opposed to foot pounds. Wrong word plural?

Because Foot Pounds are a unit of work as in 550 ft/lb per second = 1 horsepower

A pound foot is 1 lb force acting on a one foot lever - no work done

It's ok for the average guy to mix up his units but when it happens in engineering manuals and on tools it's too much IMHO






Apparently I'm not the only one it annoys

[Mike Tashjian]

First time I heard Pound feet was on Motorweek in the early 80's. It may be correct, but not the way it was taught in any school or college I attended in the seventies. Since it was imprinted in my brain back then, I don't think in my mind it will ever change it.  I understand it is not right but that will help me much.  Mike

[Kiwi_Roy]

I picked up a digital luggage scale, it reads out in pounds or kilograms, it seems to align nicely with the click
of my wrench.

Re pound feet / foot pound
At high school, we had a Physics instructor, Mr. Webber, needless to say he was nicknamed "Spider" but never within his hearing. He was a real stickler for getting the terms correct and had you learning all the laws of Physics by heart.
He used to recite passages from a text book and waited for us to write it down, one day I realized he was using me to set the pace, I could speed up or slow down the class just by looking up, or keeping my eyes down, I always looked forward to his class, he was a big influence.

[John A]

In the old Allison engine fuel control manuals it specifies inch/ounces for things, I don't know if Rolls Royce rewrote those or not. Thirty five years ago I heard that NASA did a study and found that the most consistently accurate torque  of fasteners was achieved by an experienced mechanic doing it by feel. I have tried to find that document but haven't been able to so I wonder if that is an urban legend . I like to use my torque wrenches but would hesitate to use one on a drain plug, for that I use the ever popular "feel"

[biking sailor]

So...

is "Foot-Pounds" a number of pounds at one foot and "Pound-Feet" a number of feet at one pound?   ;D

Love to stir the pot!

[acogoff]

    One of my farm trucks has the older Budd stamped wheels and they are to be torqued to 400 foot pounds, so a 3/4 breaker bar with a long pipe extension are used. I figure out where my 180 pounds has to stand along that pipe to achieve this torque-2.222 FT. Stepping off a stool with all my weight on one foot at that point gets the proper torque. So you could say it's 180 pounds on one foot. If two feet were used it would be called Feet Pounds. This is getting a bit off topic though- ft lbs , pounds feet who cares.

[Chuck in Indiana]

In the old Allison engine fuel control manuals it specifies inch/ounces for things, I don't know if Rolls Royce rewrote those or not. Thirty five years ago I heard that NASA did a study and found that the most consistently accurate torque  of fasteners was achieved by an experienced mechanic doing it by feel. I have tried to find that document but haven't been able to so I wonder if that is an urban legend . I like to use my torque wrenches but would hesitate to use one on a drain plug, for that I use the ever popular "feel"

Ed the Rocket Scientist (really) told me the same thing. It was an internal study, and may or may not be available.  ;D

[Chuck in Indiana]

Now that's the way to do it.
 

Ichybon rox.. ;-T

[pyoungbl]

In the last week or so I saw that BMW is recalling (oh they don't call it a recall...something like a technical adjustment) about 300,000 R and K bikes to replace a rear hub.  They say that the problem is due to owners using too much torque on the bolts holding the wheel to this hub.  This makes me wonder if it's merely a case of blame shifting or that we are all a bunch of klutzes. 

Peter Y.