Do torque wrenches need to be annually calibrated?

[hollowch]

I've got a torque wrench that I acquired from a buddy a few years ago. It's a really nice "Clicker" type wrench that goes from I believe 10-100 ft lbs..

Anyways... It doesn't feel like anything is wrong with it... I was just wondering if it was advised to keep those things calibrated...? Especially because I'm using it to put my motor back together where things need to be really within spec on the bolts...

 

[demesauce]

No. It only requires calibration if you drop it. And even if if is dropped it mostly likely will continue to work great. And good luck finding a place to get it calibrated, you'll have to find a high end tool store

 

[viper982]

If you see any tool trucks cruising around they usually have a torque wrench torque tester on board so you can see how far off or on your torque wrench is.

 

[broncnaz]

really all depends on how precise you want it to be and how much you actually use it. last place I worked did them annually and when ever they were dropped. all our stuff had to be within 5% if it wasnt we got a new one you would be superised at how often they do get out of range. Usually the lower range wrenches seem to go bad quicker than one with higher ranges. We also didnt use the bottom 20% of the scale as they tend not to be as accurate at those settings.
All in all for a basic engine rebuild its probably not a issue although I would want a little bigger torque wrench to hit some of the higher torques. so really unless you use the torque wrench daily yearly calibration is not required but you never know if your buddys torque wrench is good to start with a feels like its good means little. Also always return the torque wrench to zero or its lowest setting on the scale when not in use.

 

[Bronchole]

always return the torque wrench to zero or its lowest setting on the scale when not in use.

What he said.

 

[RIbronco]

It should be fine. I use to have a dozen or so torque wrenches calibrated on a six month cycle. It was unusual for one of the wrenches to require adjustment, even after hundreds of cycles. Granted these were production quality tools, but you mention the one you acquired was really nice, so it likely falls into this category. Typically, its the real cheap stuff that has a tendency to consistently require adjustment.

Either way, most of the variation in fastener tension is from the friction of the threads and under the bolt/nut head. The torque wrench can be dead on accurate, but the fastener tension can still be as much as 20% from target.

If you want to have it checked out, look up a calibration or metrology lab in your area.

 

[Wyflyer]

It depends.. My son works in a helicopter assembly plant. They have wrenches that are calibrated for tightening, some for loosening, some for both tightening and loosening. They calibrate annually.
But for building engines few people calibrate them. And I've never heard of an engine failure because the torque wrench was off by 10%

 

[Apogee]

...Also always return the torque wrench to zero or its lowest setting on the scale when not in use.

X2...I destroyed the case on my ATV race engine due to a weak click-torque wrench spring, so even if you don't have your wrench calibrated regularly by a professional, it would probably be worth it to have a beam-type torque wrench on hand for comparison's sake, that wayy you can get your own second opinion whenever you need or want it.

 

[Broncobowsher]

Our work is crazy about calibration. I can get paperwork that traces all the way back to the national sandards. Trust that a lot more then a tester in a parts store that is probably further out of calibration then the wrench you are trying to test.

to that I know our torque wrenches have a stable history. But storing them relaxed is important. Keep them clean and lubed. If that spring startes getting any rust on it the spring rate dies and the wrench is junk.

 

[hollowch]

I'll admit that I have certainly dropped the thing a few times... I honestly had ZERO idea that it was a big deal... And I don't recall ever stripping the wrench to its lowest setting during storage... CRAP

I think I'm going to go buy a beam-type wrench so I can compare the two...

 

[Apogee]

The other aspect is to use common sense and get a good feel for what 25, 50, 75, 100, 125 ft-lb feels like. In my case, I was torquing the main drive gear to 48 ft-lb and it was probably only half that...if I hadn't been reassembling the bottom end on my quad at 1:30 in the morning the night before a race, I probably would have had a much better chance of noticing that something didn't seem right the first time, but instead I did it twice with the same torque wrench and failed it twice.

Considering what a torque wrench costs versus and engine, transmission, etc, a decent wrench seems like a pretty good investment.

 

[Skiddy]

What he said.

yep number one reason they get out of calibration. I calibrate ours here every 6 months. out of about the 100 or so i do maybe 2 out of them are out of tolerance. biggest problem we have is they don't stop after the click and end up stripping the gears in them also not meant to use as just a ratchet

 

[73azbronco]

only need calibration if ythe job requirs it, like nuclear, aircraft, etc.

Testing is not a bad idea for shops as they use the heck out of them.

Occasional home use, I never had one tested, but have had a few fail while using them.

Which is why I always keep a selection of beam torque wrenches around, those never go out of tolerance.

 

[BwoncoHowie]

A lot of excellent responses here.

If you havent dropped it or banged it too hard, it's probably pretty close. As others have stated turning it off or to the lowest mark when not in use is one of the best ways to preserve accuracy. If it was used several times a week, it may need checking every few months. If you dont use it very often chances are its in good shape. If you know nothing about it's history, get it checked B-4 using it. Also, your 10-100 wrench will be more accurate between 25 and 85 if you need lower or higher torques to be accurate, it may be better to get another torque wrench that can be used in it's sweet-spot or the middle ranges.

A torque wrench is a precision instrument and should be cared for as such.

Like Broncobowsher said: "...to that I know our torque wrenches have a stable history. But storing them relaxed is important. Keep them clean and lubed. If that spring starts getting any rust on it the spring rate dies and the wrench is junk. "

IMHO I dont trust chinese torque wrenches as evidenced by their piss-poor QC practices. If you need to purchase another, try a well known brand like proto, williams, snap-on, craftsman, or armstrong.

 

[jw0747]

calibrate it only if you're building an Indy car or NASCAR engine.

 

[Larry B]

My wrinches are all top quality and I have never had a problem with any them. Only worked for one Cat dealer where we could check the wrinches. Bronco and heavy equipment are not airplanes and goverment work. As said befor keep it backed off when not in use.

 

[bax]

Matco Toll guy here. Yes storing them "relaxed" is a must. Getting them recalabrated is not that much money. 35 bucks plus shipping is the average cost for a clicker type. The digital ones are more. I send one in every week it seems. for what ever reason. Things I know that messes them up. Continuing to tighten after the click. backing the handle off so far it falls off. Storing it "set" Digital ones must never be torqued past there designed rating. They will show an ''Error" code every time. Lots of head bolts now require angle torque measurements. yeah you need a good tool.

 

[BronCowie]

Matco Toll guy here. Yes storing them "relaxed" is a must. ...

Dang!!! I just ran to my tool box and zero'd out my t-wrenches Live and learn.

 

[bax]

Dang!!! I just ran to my tool box and zero'd out my t-wrenches Live and learn.

Good man. I forgot to add. Setting them to zero at night is the worst thing you can do.

 

[BronCowie]

Good man. I forgot to add. Setting them to zero at night is the worst thing you can do.

I'm upsidedown now! ?:?