Torque wrench

I do a rough check once in a blue moon, but as long as you're unloading it after each use they will last forever.
 
Thing is, its an old one not a digital one (Not sure if digital ones stay more accurate). By unloading do you mean wind all the way down as i only tend to use it on wheel nuts at 130Nm/135Nm depending on car so to go to 0 is a big thing.
 
No it is not at all necessary to wind a torque wrench back after each use.

When I worked at Norbar we did extensive testing to see if this myth was true or not and it definitely is not true, although obviously that is with Norbar wrenches, other makes are available and may operate and react differently :)


If the wrench is wound back at all it should not be adjusted below the minimum scale marking (usually 20% of maximum) - never to zero as this can adversely affect the calibration of the wrench.

If the wrench is only used very occasionally, then it maybe classed as best practice to adjust back to the minimum scale setting after each use.
However if you use the wrench in an environment such as a commercial garage, it is perfectly acceptable to leave it set for days/weeks/months on end with no ill effect to the calibration (it will remain within the acceptable 4% tolerance) as long as the wrench is stored in a clean dry storage box between each use.

The choice is yours, either way is acceptable.

One important factor that people often ignore (usually because they don't know to) is that if a torque wrench has not been used for a few days or more, it should be set at a low to mid point torque and exercised about half a dozen times times before actual use to redistribute any grease that had dried up or been squeezed out.
 
Entai said:
No it is not at all necessary to wind a torque wrench back after each use.

When I worked at Norbar we did extensive testing to see if this myth was true or not and it definitely is not true, although obviously that is with Norbar wrenches, other makes are available and may operate and react differently :)


If the wrench is wound back at all it should not be adjusted below the minimum scale marking (usually 20% of maximum) - never to zero as this can adversely affect the calibration of the wrench.

If the wrench is only used very occasionally, then it maybe classed as best practice to adjust back to the minimum scale setting after each use.
However if you use the wrench in an environment such as a commercial garage, it is perfectly acceptable to leave it set for days/weeks/months on end with no ill effect to the calibration (it will remain within the acceptable 4% tolerance) as long as the wrench is stored in a clean dry storage box between each use.

The choice is yours, either way is acceptable.

One important factor that people often ignore (usually because they don't know to) is that if a torque wrench has not been used for a few days or more, it should be set at a low to mid point torque and exercised about half a dozen times times before actual use to redistribute any grease that had dried up or been squeezed out.
Click to expand...

Very interesting, specially as you have worked for Norbar. I am a calibration engineer, mostly electrical but i also do a lot of mechanical and pressure instruments too.

We have a regular customer who always leaves his torque wrenches set on to his specified force requirements and during the years there has been considerable amount of drift not massive but still changed. But he is happy to have it back each year and he just applies the require calculation and sets his torque wrench accordingly. I have seen many others drift and we have always assumed it to be down the wrench being left on its required settings. But none of them have been a Norbar, very interesting.

When we had a UKAS audit a few years ago and we were thinking about going UKAS for torque the auditor was very specific about the wrench being set to the minimum value possible at the end of use to increase the wrench potential lifespan. But we decided to stick with ISO calibration for torque. The auditor also mentioned about exercising the wrench before use, this is something i have also done with my personal torque wrench's but thats thanks to my dad being a engineer too.

At the end of the day its your tool and its up to you if get in calibrated. If its for business use, i would certainly get them tested. If its for personal use, its good for peace of mind like when I recently tested all mine before i done the cam belt on my wife car.
 
My torque wrench failed me while back, think it needs calibrating. How much does it cost to get it calibrated? I would guess sits not cost effective to calibrate a cheap wrench.
 
Walk into the tire department at your local Costco and ask them if you can quickly calibrate your torque wrench. They've got a digital calibration device behind the counter that their techs are supposed to use daily. They've never told me no.
 
Entai said:
Walk into the tire department at your local Costco and ask them if you can quickly calibrate your torque wrench. They've got a digital calibration device behind the counter that their techs are supposed to use daily. They've never told me no.
Click to expand...

I was about to say you've obviously not been to the one closest to me but looking at location I'd say you probably have. Imagine it very much depends who you get though, the person I last dealt with almost certainly would've declined my request :p Wheras the guys in Bham who I went to the time before that I don't doubt would've been helpful :)
 
This is interesting.

I never really had a torque wrench before but my work uses them. We don't have a calibration device, and they can't be bothered to calibrate them, so they just replace them annually.

I went over to Norway a few months ago to change one out. Was maybe used a handful of ti,es at most, so was like new. So I ended bagging an almost unused Norbar one.

I'll maybe try at my local Costco and see if they will oblige with a quick calibration.

Policy dictates we always wind our bars back to zero anyway. So will be interesting to see how much it has drifted.

To be honest, mine is really to big anyway. The only thing it's good on is cars as it starts at around 30-40 lbft, so starts too high for most of the car stuff I do, except wheel nuts.
 
Since I only use mine for wheel nuts. I would notice if it went way out...

Be sure to unload them, that's what my brother always swears by. In his work, they just buy new ones.
 
The spring creep thing is largely a myth.

Steel or steel springs, do not fatigue/wear appreciably under moderate compression, which is all they will see in a correctly designed and manufactured torque wrench used within its design limits.

Springs fatigue/wear when rusted, abraded, heated, taken beyond design limits, impacted, vibrated, or cycled ~10 million cycles. More wear or fatigue takes place during the adjustment process, as each one is counted as another cycle.

The common coil spring can be thought of in exactly the same way as a straight steel beam. The beam will fatigue from being flexed/bent too many times, or by the onset of corrosion, but never from simply holding a static weight within its capacity range.

Steel doesn't fail from just sitting there holding some weight, unless the other above factors are introduced. A straight beam can sit under moderate load for 1,000+ yrs w/o fatiguing, provided it doesn't corrode, there is no reason a correctly designed manufactured spring will not do exactly the same thing if treated correctly, and if it is always used within design limits etc.

As I said earlier we tested the myth by having around 40 wrenches of different sizes and ranges. half of them were set at various loading ranging from minimum to maximum settings. and left for a year.
The other half of the wrenches were set to a load used on a few bolts, then reset back to minimum scale setting, this was repeated daily, for a year.

At the end of the year, all the wrenches got calibrated.

Those that had been used daily and cycled daily, had all drifted at least 2% from their original calibration figures.

Those that had been left statically loaded all year were all no more than 0.1% away from their original calibration figures/

Cycling torque wenches frequently will result in more chance of it being out of calibration than those left at a setting, and not cycled back to minimum scale settings after each use.
 
Chaps,

I am asking for help to choose & source a couple of reliable torque wrench's - so I can self service our cars (to save cost).

I have learned the hard way - with tools - buy crap buy twice.

I am asking for some advice & help in sourcing refurbished/end-of-line high quality torque wrenches that will be available at significantly lower cost.

That is the only way I'll be able to afford quality units that I can know work and are reliable.

Can you help guide me reach this goal?

I'm reaching out for your help.

Hope you can help,

Marantz.
 
Entai said:
The spring creep thing is largely a myth.

Steel or steel springs, do not fatigue/wear appreciably under moderate compression, which is all they will see in a correctly designed and manufactured torque wrench used within its design limits.

Springs fatigue/wear when rusted, abraded, heated, taken beyond design limits, impacted, vibrated, or cycled ~10 million cycles. More wear or fatigue takes place during the adjustment process, as each one is counted as another cycle.

The common coil spring can be thought of in exactly the same way as a straight steel beam. The beam will fatigue from being flexed/bent too many times, or by the onset of corrosion, but never from simply holding a static weight within its capacity range.

Steel doesn't fail from just sitting there holding some weight, unless the other above factors are introduced. A straight beam can sit under moderate load for 1,000+ yrs w/o fatiguing, provided it doesn't corrode, there is no reason a correctly designed manufactured spring will not do exactly the same thing if treated correctly, and if it is always used within design limits etc.

As I said earlier we tested the myth by having around 40 wrenches of different sizes and ranges. half of them were set at various loading ranging from minimum to maximum settings. and left for a year.
The other half of the wrenches were set to a load used on a few bolts, then reset back to minimum scale setting, this was repeated daily, for a year.

At the end of the year, all the wrenches got calibrated.

Those that had been used daily and cycled daily, had all drifted at least 2% from their original calibration figures.

Those that had been left statically loaded all year were all no more than 0.1% away from their original calibration figures/

Cycling torque wenches frequently will result in more chance of it being out of calibration than those left at a setting, and not cycled back to minimum scale settings after each use.
Click to expand...

Entai,

Reaching out for some guidance.

Can you help?

Marantz1870
 
I always unwind mine, doesn't take a moment, so will keep playing safe. I'm an engineer and understand the importance of calibration. But for most home users it's just not necessary. I use mine for wheel nuts, suspension bits. Nothing that needs to be super accurate. If you're using it all the time for building engines and such like, then it might be a wise investment.
 
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