Technical Torque Wrench care and storage

I’ve got a Craftsman torque wrench, had it for 30+ years, always stored ‘unloaded’ (set to zero), hangs on wall in original box. Working on O/T truck, needed spindle nut set to 138 ft/lbs.

Tightened it to what I thought was close, put torque wrench on and was surprised I didn’t need cheater bar to get a ‘click’.

Can they go out of calibration and how would you check?

 

We turn ours in to the local NAPA and they send it in for checking and adjustment. Absolutely they go out of adjustment.

 

Yup, they do. I've had 2 go out of calibration.

 

Some Snap on trucks have a gizmo on board that an verify if your torque wrench is in calibration

 

I send mine into the Mac Tool guy that comes to our shop. Also, I have several different torque wrenches for different jobs. My engine wrench is only used on engines, my other 1/2 drive wrench is used on the other mundane stuff, such as lug nuts. Yes, I torque all lug nuts I put on. I also won’t torque past 75% of the wrenches rating. Example, my 3/8 goes to 100 foot pounds, I won’t use it past 75 foot pounds, if I need more than that, I get one of my 1/2 drive wrenches.


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Yes, click type wrenches can and do go out of calibration.
Leaving them in a tightened condition for much more than an hour or so, having other tools dropped on them, throwing/dropping them onto hard surfaces, heavy usage, using them to their maximum torque value...ALL lead to quickly going out of calibration.

I keep a well cared for "beam" type to do my own "quick" check of my click wrench. I had the beam type verified many years ago, and just use it for double checking of my 1/2" drive. I do the same with my 3/8" drive wrench.

Mike

 

I also think there are rebuild kits available if they don't work at all. Still, you'll have to get it recalibrated periodically.

 

This^^. Torque wrenches are most accurate in the center 80% of their range. I too torque every wheel nut that goes on.


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Thanks to all, will get it checked

 

I bought a craftsman several years ago. Caught it on sale for 69.95, when I bought it they offered a 3 year replacement warranty on it but it had to be sent in once a year for calibration to keep warranty valid. One year went by so I took it to the repair center here. I told them I needed it calibrated. Guy at the counter didn't have a clue.... So he asked his manager. The manager had to make a phone call to find out. 30 minutes later he comes back and tells me they have to ship it to Chicago to be calibrated, would take 3-4 weeks and would cost 65.00..... Plus shipping.

I threw it away and bought a Snap On.

 

If you have access to a bending beam torque wrench, you can check the accuracy of your clicker type wrench. Set the clicker to say 100 lb-ft and hold it in a vise. connect it to a bending beam wrench. You either need a 1/2 in square to square socket or I think an 11/16 12 point will work. Make sure the indicator on the bending beam wrench is at zero. Then pull 100 lb-ft with the bending beam wrench; if the other wrench is accurate it should click.

 

I’ve had one (clicker ) for many years,,,and it works great,,,,,,I also have two old beam types,,,they work well also,,,,nothing wrong with a beam TQ wrench .
I even bought a new fangled electronic one,,,it is a box about the size of your fist,,,has a 1/2 inch fitting on top,,and a 1/2 inch male end on the bottom .
It turns any breaker bar into a torque wrench .
You program in the desired torque and it beeps when reached .
I thought,,,no way it is accurate,,,,,tested it against my clicker wrench and both beam style .
All of them were within 1 pd,,,,every time .
I went through several different settings,,,,,just to be sure .
They all matched the electronic one 8 out of 10 times,,,,dead on !

Oh well,,,,maybe the new stuff is okay after all .
But,,I still like my beam type,,,,and I love my clicker .
Go figure .

Tommy

 

I bought ARP head studs for OT Cummins powered Power Wagon . ARP says torque to 125 lb ft of torque . I go up in stages , 35 , 70 , 90 headed to 125 . Three of the studs stripped the threads . ARP says torque wrench is off , I tried 3 all three stripped threads at 90 . Hard for me to believe 3 are off by 35 lbs . After 3 weeks ARP says we will refund purchase price , no labor or gasket costs and you can keep the studs . Does this sound a bit strange to you ? Anyway , I get mine checked once a year . Non have been off calibration . I always set to lowest reading on the range not 0 when stored . I never torque past the CLICK . Screw ARP also . I hate to say it but I think off shore is in their business now also .

 

I worked in the aviation industry for more than 4 decades. Our torque wrenches had to be calibrated every 6 months. I would think that if you took yours to the local airport there would be a calibration device at your disposal...most airplane guys like to be helpful.
Our QA (quality Assurance) department took care of the tool store and calibration requirements.

 

"Screw ARP also . I hate to say it but I think off shore is in their business now also"

I don't think that's a fair thing to say about ARP.
From their site, They are proudly made in the USA, "100% of Fastener Manufacturing Is In-house at ARP"
Reading up on their website (or printed catalog) is quite informative.
They are a quality manufacturer.

 

In my youth I worked at Western Forge who made wrenches, screwdrivers, punches, and torque wrenches for Sears Craftsman Tools. Each month I would purchase a complete line of tools from all the current manufacturers and run a complete quality test on them. In that day and age you would be surprised by the high dollar lines that would fail. Also when you would take a tool back to Sears that had the WF symbol on it, I was required to determine why it failed. (Lots of screwdrivers were used as chisels. And the amount that fell into a saw blade was crazy. Sears replaced them even when due to stupidity.)The beam torque wrenches made by Craftsman were the outstanding tool. The super accurate shaft/hole sizing was held to a critical tolerance resulting in a perfect repeatable reading. If you threw the wrench into the bottom of your tool box and the indicator beam got bent all you had to do was bend it back to zero and use the wrench as new. In the years I tested, there never was a beam torque wrench that read wrong. Clickers, well that is another story. So the advice of checking your clicker against an old fashion beam wrench is valid and highly useful.

 

I calibrate my own wrenches. Put a big dumb socket on the wrench, secure the socket in a vice with the handle in the horizontal position and hang a accurate weight at the center of the grip. Some beam types have a pivot in the grip so use that area. Measure the distance from the string that you use to hang the weight to the center of the square drive. If a 25 lb. weight is used and the distance is 2 feet it should read 50 ft./lb. If the distance is 1.5 ft. it should read 37.5 ft./lb. (Caution mathematics my get involved with odd distances)! Simple, accurate, no waiting time or shipping. I use my grandson's barbell weight after checking it's accuracy and mark the distance on the wrench.

 

I never use one of those wind up ones as they do need to be checked. I had one go out of spec when i was an engine builder some time back and since i only use a Dual Signal type. JW

 

So if it's not correct, do you correct it or make a note of it and adjust the setting accordingly?

 

On the old beam wrench I simply bend the pointer. I have a fancy dial wrench that you can rotate the dial to the correct value. I don't have a clicker and dunno on that un.

 

Started with a Craftsman beam style ~60 years ago and still have it in addition to some various brand clickers of different capacities, find them handier to use when it's hard to position yourself to see indicators. Used clicker and dial types at work on the RR, some jobs requiring a clicker calibration check against dead weight testers in the shops when set for different values. Always back off clickers at finish of any job .

Never cared for the dial type simply because I never had the capability to fully adjust the calibration should it be discovered off anywhere in it's range. I try to avoid using any style at the extremes of their ranges.

lost availability to check my home wrenches when I retired so bought a HF digital torque adapter (I know, I know, but it continues to check out on the marks with my beam) for ~$30 to use for checking them and avoid the down time and hassle of taking or shipping them away for checks. So far working out well for me and until it doesn't I'll continue the same MO.

FWIW all the spec sheets I've seen say beam types are accurate to 2%, clicker and dial types are accurate 3 to 5%.

Ed

 

I've always used the Snap On dial type torque wrenches which I bought new. I really have never even looked into having them recalibrated as I'm the only one that ever used them and they're treated like fine china.

 

Very interesting to hear about the Craftsman beam type wrenches. I've seen them at swap meets for a buck or two, which in a way is kind of sad.

I prefer the click type when working on an engine in chassis as sometimes it is difficult to get a straight on reading with the beam type, which will result in error.
Even if the click type is a little less accurate, at least it should tighten all the fasteners to the same value.

 

I still use the same Beam Style that I have had for 45 years. Never have to get them calibrated.

 

Important with the spring loaded click type is when you dial it down to zero you don’t bottom out the spring as this puts a negative tension on the spring and throws them out of calibration.

I have all snap on click 1/4 3/8 1/2 3/4
And dial as well.
All serve different jobs.


But if your putting a cheater bar on a torque wrench your not torquing the fastener correctly.
A torque wrench is calibrated by the socket end to the end of the handle.

 

That's the main benefit in my opinion, not only are fasteners tightened "just right", they are all tightened very, very consistently. One thing about torque wrenches that people often overlook, they are definitely not a "one and done" operation.

Fasteners need to be checked after use, after heat/cool cycles, and re-torqued (in the tightening direction) until they stabilize.

 

As far as tightening evenly torque is not great at it, friction of the threads accounts for approximately 90% of the torque application, 10% actually goes to stretching the fastener. Torque by angle is much more accurate and torque to yield puts the bolts into the plastic deformation stage which provides much more stability through heat cycles etc.


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Good reading on torque wrenches

https://www1.snapon.com/display/231/ToolNews/TechRefs/2008/TorqueWrench08.pdf

 

We have a torque wrench checker at work so the guys on the floor can spot check theirs.

I borrow a torque wrench when I need one, have used S&K and Cornwall on my SBC assembly, did compare 2 of them and they were very close. I HAD a garage-sale Craftsman beam type I got at age 17... that got lent out by my brother and it never came back. I torqued a lot of stuff with that and we never treated it with respect.

 

My Craftsman clicker "locked up"; could't tighten or loosen. Course by then, Sears had quit servicing them, and now they're gone. Sent if off to TeamTorque.Com, who said they could repair it. They could't, so I bought two off of E-Bay that had never been used. I am Butch/56sedandelivery.