Verifying dirt cheap torque wrench.

[King Bojack]

I had a coupon for a 10 dollar 1/2" HF click type torque wrench so I figured what the hell I'd bet 10 bucks on it. So I took it home and found a random nut in my car, put it finger tight then set the TW to 60 ft/lbs. I turned till click (which is mushy as hell on this wrench).

Then, I got out my 3/8" Craftsman beam style and turned until the nut just started to turn and it was around 60 ft/lbs measured. This seemed to me to prove that at least out of the box the HF TW is accurate... for now.

Was this a decent test of a torque wrench?

 

[Kirbot]

I'm also curious to hear about this.

I picked up a $10 3/8" torque wrench a few days ago.
It actually feels great, fit and finish is just fine, I'm just curious about the accuracy.

I'm sure it's close enough for my needs, but it would be interesting to know exactly how it compares to some of the big names.

 

[bchee]

I haven't tried this but I think a more accurate test is to use a weight scale somehow.

I don't much about beam-types but I would like to try one if they never need calibration.

 

[diggerrick]

I had the $9.99 1/2" HF torque wrench for awhile. My biggest beef with it was repeatabilty. It might set a couple head bolts fine, then leave a couple loose and a couple tight, so I sold it in a garage sale for $15.

I was doing the same as the OP - following with a recently calibrated wrench as a test only, then pulled everything apart and reassembled with the "good" torque wrench.

 

[King Bojack]

I was doing the same as the OP - following with a recently calibrated wrench as a test only, then pulled everything apart and reassembled with the "good" torque wrench.

Was the good torque wrench digital or beam style? Cuz a good clicker will only tell if you if the HF TW failes to tighten to specified amount. If the HF overtorques like mad then I dunno if you can verify that with a good clicker.

 

[chancez]

The way I checked my harbor frieght one was to put a 1/2" 8 point socket on it and put a beam style in the other end of the socket. Mine checked out exactly at multiple torque settings.

 

[ajchien]

The way I checked my harbor frieght one was to put a 1/2" 8 point socket on it and put a beam style in the other end of the socket. Mine checked out exactly at multiple torque settings.

This is exactly what I picked up from GJ also. I have a nicer beam style wrench, to which I put a 8 point socket on, and fit the clicker into the socket. Then watch the beam until it clicks.

I've got 3 el cheapo torque wrenches, 2 from HF, one no name. 1/4 is off by 2 ftlbs, 3/8 off by 5 ftlbs, and 1/2 off by 5 ftlbs. Yet mine are repeatable throughout the scale.

 

[bchee]

I'm guessing you put the beam one in a vise?

 

[MattT]

If the HF overtorques like mad then I dunno if you can verify that with a good clicker.

The way I check "calibration" with a good clicker is torque bolt to say 70 ft/lb with the suspect wrench. Then set the good one to 65 ft/lb bolt shouldn't move. Then crank it to 70 bolt might move a bit. Then 75 and the bolt should definitely move.

This is the method I use to check my 3/8" and 1/2" torque wrenches against each other.

 

[oldtools]

Why don't you test it with a digital torque adapter. When the torque wrench click, read the torque value from the digital meter and compare the two.

http://www.amazon.com/dp/B004FEI2ES/?tag=atomicindus08-20

 

[Uncle Ben]

"Kirbot": did you have a coupon for the 3/8" HF torque wrench for $10? If so, did you find it online? The cheapest I have ever seen the 3/8" clicker is $20 and I only have a 1/2" at the moment. Thanks

 

[HandyManny]

This is how I verified mine, just like the OP did. I do this about once a year or more depending on how much I use mine, which is really for rotating tires anymore.

I was no longer willing to pay to have my old Proto clickers recalibrated since I no longer wrench professionally.

For home use I bought a $20 Walmart clicker torque wrench about 10 years ago and it was accurate right out of the gate and has held it's accuracy over the years pretty well. Nobody would even bother recalibrate a wrench like this one if it ever does become off or inaccurate. But for $20 and going on 11 years of occasional use in my garage, that's not bad at all.

 

[gj67stang]

Why don't you test it with a digital torque adapter. When the torque wrench click, read the torque value from the digital meter and compare the two.

http://www.amazon.com/dp/B004FEI2ES/?tag=atomicindus08-20

I've done that. My $10 1/2" HF was more accurate than my two Craftsman clickers!

 

[bitbycarbug]

I had a coupon for a 10 dollar 1/2" HF click type torque wrench so I figured what the hell I'd bet 10 bucks on it. So I took it home and found a random nut in my car, put it finger tight then set the TW to 60 ft/lbs. I turned till click (which is mushy as hell on this wrench).

Then, I got out my 3/8" Craftsman beam style and turned until the nut just started to turn and it was around 60 ft/lbs measured. This seemed to me to prove that at least out of the box the HF TW is accurate... for now.

Was this a decent test of a torque wrench?

How do you know the beam style is accurate? All you do is verify that the clicker and beam are accurate to each other, but both could be off by the same amount.

Will it matter for anything the home mechanic does? Probably not, unless you're rebuilding race engines and such. Lug, Suspension, and outside motor torque ratings should be pretty good within a couple of ft/lbs. Inside the motor might be a different story.

 

[SuperSocket]

$10 bucks?! damn, I thought my $20 deal was good.

 

[MrMark]

That test only proved that one of your wrenches is off, perhaps significantly. They shouldn't have been in agreement. There is a difference between geting a bolt at rest moving and moving a moving bolt. Amazing how often this comes up

 

[MrMark]

I have a brand new Armstrong wrench that I also sent in for calibration (it was off out of the box as I suspect many are) that I will play around with some of these backyard torque auditing procedures and see how accurate they are. I'll try the auditing with an SK beam type and with the clicker method Matt uses and see how far off the dynamic vs. static torque appears to be. The dynamic (accelerating) torque may even be lower than static if significant relaxation has occured.

 

[HandyManny]

That test only proved that one of your wrenches is off, perhaps significantly. They shouldn't have been in agreement. There is a difference between geting a bolt at rest moving and moving a moving bolt. Amazing how often this comes up

It is possible. But typically Beam style torque wrenches retain their accuracy if not stretched passed their limit or exposed to extream heat or cold.

 

[stopdroplol]

How do you know the beam style is accurate? All you do is verify that the clicker and beam are accurate to each other, but both could be off by the same amount.

The beam style wrench is actually the most accurate way of measuring torque there is. It's just comparing the angle of something at rest to torque deflection. As long as the needle points to 0 at rest, and the scale hasn't been tampered with it will always be accurate. The only error that can occur is user interpretation error. If you were to build a massive one, with a massive scale, you would be able to set torque limits perfectly.

 

[cglasgow]

I was surprised by the HF torque wrench:

I've got a couple if old CM wrenches -- a 3/8" (44541) and a 1/2" (44476). I have always treated these wrenches fairly gently and always wound them all the way down when not in use.

The company I work for is having a bunch of stuff calibrated right now so a calibration company has their trailer parked in our parking lot. I asked them if they'd be interested in doing some work on a cash ticket and they said, "sure."

I gave them the two CM wrenches. The 1/2" has never been checked and the 3/8" was last calibrated about 20 years ago. (I know, I know....) Both failed. The 3/8" was out about 8% (tolerance is 4%). The 1/2" was out 50% (five zero percent)! Turns out the jam nuts that hold the handle onto the adjustment screw came loose and the handle shifted, throwing out the calibration. I searched online and found this is a common problem with this wrench -- especially is you wind it to zero "with authority." They want another $40 to repair it but there's not another calibration charge.

I may let them fix it, but in the meantime I wanted another wrench and saw HF had their 1/2" wrench on sale for $24.99. With a 20% coupon, that puts it less than $20. "What the hell," I figured, "let's give it a try." I bought one and gave it to the cal folks to see how far it's out. That way, I'd know how much fudge factor to figure in.

The damn thing passed!

He said the tolerances are a little looser than he would have liked, and he didn't know the manufacturer's spec so he assumed 6% (his generic spec). He said it would not have passed 4%. He also said it will probably go out quicker than a higher-dollar wrench. But he also said that he does a lot of work for the Navy (his co. is located near a base) and they buy SO by the case. He finds that a large number of them are out of spec straight out of the box. So I have more respect for this $20 HF wrench than I expected to have!

EDIT: For the record, the manufacturer is Hsian Dai Co, Ltd., of Taiwan. I found little about them on the web other than that they are a Taiwanese tool manufacturer. There's no identifying info on the wrench itself apart from a serial number -- not even a COO -- but the mfr name is on the blow-molded case.

http://garagejournal.com/forum/showpost.php?p=1384516&postcount=26

 

[bchee]

I have a brand new Armstrong wrench that I also sent in for calibration (it was off out of the box as I suspect many are) that I will play around with some of these backyard torque auditing procedures and see how accurate they are. I'll try the auditing with an SK beam type and with the clicker method Matt uses and see how far off the dynamic vs. static torque appears to be. The dynamic (accelerating) torque may even be lower than static if significant relaxation has occured.

I'm interested in your results when you do it. Thanks

 

[Coach James]

When testing a torque wrench, it it is accurate at one setting, does that mean it is accurate at all settings? Wouldn't you need to test it at at least two different settings to know it was accurate?

Coach