Torque wrench minimum 'clicking' threshold?

[Michael_in_DE]

This is not another 'how to store a Torque wrench' thread.

This is about the actual usage. So I have been told and have seen where if you have, say a 5-75 ft-lb Torque wrench and you try to use it for the 5 ft-lbs it will not actually make the clicking sound/feel. So in other words the TW does not work as designed for the very low end of it's range?

Does anyone know at what range the clicking actually starts?

 

[Wakefield]

My old Craftsman 1/2" drive clicker doesn't always click at really close to the minimum setting but exercising it by making it click on "righty tighty" seems to help it click in the "lefty loosey" direction
there should still be a bit of freed motion at the point that the click should have occurred
better to use the lower capacity 3/8" drive one for torques much below half of the capacity of the bigger one

Have a lower capacity inch pound one for using on Briggs/Tecumseh engines and such,best not to trust the big torque wrenches on those things in my opinion
75 ft. lb. one maybe shouldn't be trusted at,say,less than 20 ft. lbs. even if the scale goes down lower

 

[Wrench97]

Even the high dollar wrenches will not always click at the lowest setting, but you can feel the head give or move over break point.

 

[ObnoxiousFumes]

Sometimes it just clicks so faintly you don’t notice, have to pay close attention and listen carefully. But I agree they probably shouldn’t be relied on for accurate torque readings when set that low.

 

[Komet]

It's subtle on the low end, especially on the in. lbs. units. You have to feel for the slight give of the handle. If the wrench is brand new, try getting it to click at a few different positions 20-30 times and then go back and try a light click. My Pittsburgh torque wrench needed a little breaking in that way.

 

[dnschmidt]

Most noticeable on the split beam (Precision Instruments) type of torque wrench. These can be so faint on the low end that you'll barely hear it in particular if you've ever gone to a WHO concert.

 

[ItsNemo]

They're also less accurate on either end of their scale...I forget the exact percentage, but they say don't use them on the upper 10% or lower 20% or something parts of their scales.

 

[Schurkey]

Cram a nice, long extension between torque wrench and socket. Makes the clicking noise louder.

I have zero issue with using a torque wrench at the top of it's rated torque. The problems are at the low-end. Industry standard was the useful range was from 20%--100% of the max rated torque. Plenty of manufacturers are now selling torque wrenches that go from 10% to 100%, and I'm VERY suspicious of them.

 

[visionguru]

So in other words the TW does not work as designed for the very low end of it's range? Does anyone know at what range the clicking actually starts?

No, TW "clicks" in the full range. The problem is that people have different sensitivity and experience. A faint "click" can be easily missed.

TW is basically an adjustable, calibrated spring. Nothing complicated or fancy. At the lowest setting, the spring is the longest, has the lowest tension, thus produces the faintest "click".

Click type TW requires the user to feel the "click" and stop. Even if the "click" is felt and you don't stop quickly, you will over torque the fastener. The key is to go slow when reaching the specified torque. If you are not using TW everyday, exercising and getting used to the faint clicks before actually torquing the fastener helps too.

Electronic torque wrenches are way better in terms of reducing user error.

 

[cherokee]

My rule of thumb has always been you want it in the middle of the range, plus it gives me a reason to buy another toy.....err tool.

And if my wife ever reads this, See I told you so.

 

[finn]

Torque wrench accuracy is usually quoted as a percentage of full scale reading. That means that a torque wrench that reads up to 200 ft lb, will be accurate to within 4 foot lbs. Not very accurate if you are using it to tighten a fastener to five foot lbs. The actual value will be somewhere between four and nine ft lbs in that case.

 

[PBCampbell]

Torque wrenches have long and I mean loooonnnng been 20-100% of scale for stated accuracy and that goes back to deflecting beam type wrenches. It's only been since electronic torque wrenches utilizing strain gauges that we've seen 10-100% of scale wrenches. More to answer the original question with a spring type (micrometer) Torque wrench it's the reactionary force of the spring that makes the click (more or less), less force (lower setting) means less force to make sound.

 

[MarcSeattle]

There are new designs that are more accurate at the extremes of the range. I recently bought a Hazet 5122-2CT 40–200Nm torque wrench and the calibration sheet shows it averaging only 0.2Nm off at 40Nm, 2.0Nm off at 120Nm, and 2.5 Nm off at 200Nm (five test pulls at each level).

 

[PCustoms]

They're also less accurate on either end of their scale...I forget the exact percentage, but they say don't use them on the upper 10% or lower 20% or something parts of their scales.

This is the answer.

 

[ronkz650]

Click type, not reliable below 20% of range, and the click can be missed as mentioned. I have among many, many, a 5-75 ft/lb Craftsman from 1982, and a CDI 5-75 ft/lb from 2011. Both you can barely feel the click at 5 ft/lb, but the Craftsman is dead on accurate, while the CDI is like 40% off, but both are fine from the recommended range of 15-75, and you will feel the click fine there.

 

[ObnoxiousFumes]

if you've ever gone to a WHO concert.

But can you regret it though?

 

[The Critic]

Click type, not reliable below 20% of range, and the click can be missed as mentioned. I have among many, many, a 5-75 ft/lb Craftsman from 1982, and a CDI 5-75 ft/lb from 2011. Both you can barely feel the click at 5 ft/lb, but the Craftsman is dead on accurate, while the CDI is like 40% off, but both are fine from the recommended range of 15-75, and you will feel the click fine there.

One of the reasons why I went with the newest TechAngles. They're accurate between 5-19% of their published range, but at 4% instead of 2%.

 

[boom_bap]

Most torque wrenches range is only listed in 20-100% of their range.

IE 50-250
20 - 100
10 - 50
40-200
30-150

just take 20 percent of the max and thats your bottom end (which is already where they normally limit them)..

i don't think the end user needs to care or worry about it, just use what is listed on the wrench.

 

[MarcSeattle]

Click type, not reliable below 20% of range, and the click can be missed as mentioned. I have among many, many, a 5-75 ft/lb Craftsman from 1982, and a CDI 5-75 ft/lb from 2011. Both you can barely feel the click at 5 ft/lb, but the Craftsman is dead on accurate, while the CDI is like 40% off, but both are fine from the recommended range of 15-75, and you will feel the click fine there.

Same for me. My torque wrenches had been in use for a long time. Having better accuracy and having the use of the full range were two of the reasons I upgraded to new ones.

 

[MarcSeattle]

Here is the calibration test from Hazet showing how it is accurate over the full range:

 

[FredWanaker]

I send mine to Team Torque https://www.teamtorque.com/ . They send them back with a calibration test. The grease in clicker handles sometimes hardens and that causes them not to click. I sent one off to another lab who had it for months, they sent it back to me in pieces in a box with a note that it was unrepairable. I cleaned and lubed everything, and put it back together. It appeared to work fine. Sent it to Team Torque just to be safe, they cleaned and calibrated it again. It is still with me. I cringe at all the folks I know who tossed out good torque wrenches when they stopped clicking. They were easily repairable and inexpensive if you send them to the correct place. I also check them occasionally with a beam wrench to see if they are still close. Beam wrenches hold their general calibration forever unless they are mistreated.

 

[The Critic]

I send mine to Team Torque https://www.teamtorque.com/ . They send them back with a calibration test. The grease in clicker handles sometimes hardens and that causes them not to click. I sent one off to another lab who had it for months, they sent it back to me in pieces in a box with a note that it was unrepairable. I cleaned and lubed everything, and put it back together. It appeared to work fine. Sent it to Team Torque just to be safe, they cleaned and calibrated it again. It is still with me. I cringe at all the folks I know who tossed out good torque wrenches when they stopped clicking. They were easily repairable and inexpensive if you send them to the correct place. I also check them occasionally with a beam wrench to see if they are still close. Beam wrenches hold their general calibration forever unless they are mistreated.

Team Torque attempted to "fix" a torque wrench that had gone fubar after a friend borrowed. I got it back and it still did weird stuff - not clicking when you expected it to, plus other issues.

I sent it to Snap-On and they ended up rebuilding the entire unit for their flat-rate fee.

 

[usa#1]

I've found the easiest way to get a feel for the torque wrench at low end values is to clamp a bolt in a vise (bolt threads between vise jaws) and "practice" applying torque to the bolt until you get a good feel for the way your torque wrench works. As others have said, a lot of times you won't hear a distinctive click for low end values.

 

[visionguru]

One of the reasons why I went with the newest TechAngles. They're accurate between 5-19% of their published range, but at 4% instead of 2%.
....`

Nice that you found that page.
In reality, TechAngle is way better than 2%. For example, here is the the certificate of my ATECH3F250,

Accuracy 0.25%, with the worst case error of 0.3%. My 3/8" and 1/4" Techangles are all less than 1%.

 

[Sumboodie]

Nice that you found that page.
In reality, TechAngle is way better than 2%. For example, here is the the certificate of my ATECH3F250,

Accuracy 0.25%, with the worst case error of 0.3%. My 3/8" and 1/4" Techangles are all less than 1%.

We used to get those calibrations and PMEL would cross it out and put the actual numbers.

Got so bad if we needed 5 Snap On torque wrenches we'd order 10 and hope 5 would pass.
Craftsman, the cheap $80 or whatever ones, somehow almost always passed.

Most of our had to hold +/- 5%, so 100 lb ft could be 95-105

 

[Hannahranga]

Yeah it's kinda annoying sometimes. I've used a big norbar break back torque wrench and they're really obvious you've hit the torque value cos the handle pivots like 30 degrees (plus it gets much easier), it's a shame that style only seems to be available in large and even larger.