# Craftsman Torque Wrench Concern / Question??



## dstelk (Aug 12, 2008)

I've always wrenched on bikes by feel, but for a few reasons, am now going to use a torque wrench when applicable. I picked up the Craftsman inch/lb microtorque at Sears, on sale (25-250 in/lb range). Par for the course, I started researching things after I made the purchase and now see very mixed reviews. Also, I stinkin' dropped the thing on the tile floor the second I cut the bands on the packaging. I'm wondering if I should just start over, take it back, and get a couple beam styles (one for low torque and one for higher) for basically the same price as the $59 that I paid for the Craftsman. Or, am I just being paranoid and have a nice new additon to the tool quiver that can take at least one drop early on in its service life and still serve its purpose long term???? I hate to think that Craftsman would put out a product that's so horrible that 1 drop would render it useless, but I guess stranger things have happened.


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## timberstone (Feb 20, 2009)

Any torque wrench that is dropped is going to be useless. I have a Craftsman torque wrench that I use on my car. I mainly use it for the lug nuts. It's 12-15 yrs old and still going strong. 

Bummer you dropped yours. I say use what you have. Go to your local LBS and have them torque a bolt with theirs and see if yours matches. That would tell you if yours is toast or not. You aren't the first to drop one and won't be the last. I know there are places out there that calibrate them per ISO specs so you could check into that as well. 

Like you I was looking at that same wrench but held off only because for what I was doing at the time my current torque wrench got me by. My bigger concern with that wrench is more if 25-250 in/lb would be enough range. 

If you do some searching you will find mixed reviews and it's going to come down to what you want. Lots of people like the beam style while others prefer the click type. In the end it's up to you.

When it's time for me to buy mine I still don't know if I will go beam or click type, Park Tool or Craftsman.


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## mechBgon (Jan 28, 2007)

I'd recommend beam-style, and one of the reasons is that they won't be affected by being dropped. The spring rate of the beam is determined by its material and its physical size/shape, so you can't knock it out of calibration by simply dropping it. The indicator needle can get bent, but can be bent right back to point to zero again, and you're good as new. 

So yeah, the smaller and larger Park Tool ones are my blanket recommendation. Cheap, tough, and they give you real-time readout of the torque you're applying. And you don't have to remember to zero them out after use either. If you want them to ratchet, you can get an inline ratchet head like an Armstrong 11-944 or the nice Trident ones I found on ebay.


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## jeffscott (May 10, 2006)

mechBgon said:


> I'd recommend beam-style, and one of the reasons is that they won't be affected by being dropped. The spring rate of the beam is determined by its material and its physical size/shape, so you can't knock it out of calibration by simply dropping it. The indicator needle can get bent, but can be bent right back to point to zero again, and you're good as new.
> 
> So yeah, the smaller and larger Park Tool ones are my blanket recommendation. Cheap, tough, and they give you real-time readout of the torque you're applying. And you don't have to remember to zero them out after use either. If you want them to ratchet, you can get an inline ratchet head like an Armstrong 11-944 or the nice Trident ones I found on ebay.


Ahh the beam style can be inaccurate as well depending on the steel properties, and also bending it will definately change the steel....

Basically any torque wrench is going to be a lot better than no torque wrench....

A newer torque wrench is going to be better than an older torque wrench...

Craftsman has a life time guarantee take it back, get another....or calibrate it with a lever arm and a scale...


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## dysfunction (Aug 15, 2009)

As far as I can recall.. their guarantee does not include torque wrench calibrations.


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## mechBgon (Jan 28, 2007)

jeffscott said:


> Ahh the beam style can be inaccurate as well depending on the steel properties, and also bending it will definately change the steel....


Bending the beam is how beam-style torque wrenches work. The needle indicates the head's position, the beam bends, the scale attached to the beam shows the effective torque applied. If you manage to bend the beam so far that it can't spring back to zero, then maybe its spring rate will have changed, but that doesn't happen from casually dropping it. Dropping it from skyscrapers, sure.  The needle's function is static, so any amount of bending is perfectly fine on the needle. It just needs to point to zero when the wrench is at rest.



> Craftsman has a life time guarantee take it back, get another


Last I checked, that did not apply to torque wrenches.


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## jeffscott (May 10, 2006)

mechBgon said:


> Bending the beam is how beam-style torque wrenches work. The needle indicates the head's position, the beam bends, the scale attached to the beam shows the effective torque applied.
> 
> Last I checked, that did not apply to torque wrenches.


If the steel is repeatedly bent then the steel begins to work harden changing the reading get it....

If you actual bend the arm and bend it back then that also changes the steel properties....

90 days on recalibration....or just say it is broke and get another.


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## JonathanGennick (Sep 15, 2006)

jeffscott said:


> If the steel is repeatedly bent then the steel begins to work harden changing the reading get it....
> 
> If you actual bend the arm and bend it back then that also changes the steel properties....


Had never thought about that before. Are the changes enough to really matter? I've a small, Park, beam-style wrench that I've had to bend back into alignment a few times. I don't doubt what you say above, but how much change am I likely to have effected by a few "realignments"?


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## mechBgon (Jan 28, 2007)

jeffscott said:


> If the steel is repeatedly bent then the steel begins to work harden changing the reading get it....
> 
> If you actual bend the arm and bend it back then that also changes the steel properties....


Their spring rate is not going to change significantly from you using them within their range. If you want to recalibrate periodically, go right ahead, it's simple to do... but there won't be a lot of point to it, especially not when you're working on bicycles as opposed to aircraft.

Personally, I use Snap-On/Precision Instruments, but I do this for a living rather than a hobby. I have an old Craftsman clicker too, but don't use it much. For home/hobby use, beam-style is the best overall package in my opinion.


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## jeffscott (May 10, 2006)

mechBgon said:


> Their spring rate is not going to change significantly from you using them within their range. If you want to recalibrate periodically, go right ahead, it's simple to do... but there won't be a lot of point to it, especially not when you're working on bicycles as opposed to aircraft.The older they are the less accurate they are
> 
> Personally, I use Snap-On/Precision Instruments, but I do this for a living rather than a hobby. I have an old Craftsman clicker too, but don't use it much. For home/hobby use, beam-style is the best overall package in my opinion.


So do what I say not what I do....hmmmmm


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## jeffscott (May 10, 2006)

JonathanGennick said:


> Had never thought about that before. Are the changes enough to really matter? I've a small, Park, beam-style wrench that I've had to bend back into alignment a few times. I don't doubt what you say above, but how much change am I likely to have effected by a few "realignments"?


Again any torque wrench is better than no torque wrench, as above if it is used within its range probably within 20 %.....it will tend to get stiffer over time

Bending it (the torque arm) is what matters not the indicator...

you can see how much it bends every time you use it.


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## A1an (Jun 3, 2007)

Craftsman lifetime warranty does apply to the beam style torque wrenches (says it right on the package). This was one of the reasons I went with Craftsman.


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## Crankenator (Mar 27, 2007)

Craftsman warranty on torque wrenches is lifetime, but it's not like the warranty on their hand tools....you may get lucky with the bloke behind the counter at your local Sears, but they're pretty stiff about torque wrenches. So is every other manufacturer. Calibration is never covered although they may offer to send it off for calibration (which can be close to the price of buying a new one sometimes).

I'll respectfully disagree that dropping them means they're suddenly inaccurate or ruined...as long as we're talking click-type without dial indicators. They're a simple design and reasonably durable. Also, in bicycle applications it's not THAT vital to be spot-on with torque unless you're working on high-performance carbon frames/carbon components. You can get away with quite a bit. The torque wrenches help with evenness in multi-bolt patterns and not cranking the crap out of your stem, seatpost clamp, or rotors.

I know a lot of people disagree on dropping a wrench, but in my experience and after talking to a calibration shop, I feel pretty safe that it isn't the death of a wrench. You're more likely to crack a plastic handle or lockring than you are to affect the calibration unless you drop it from pretty high up.

Here's a link to the guts of most click wrenches if you're interested: http://www.tegger.com/hondafaq/torque_wrench/index.html


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## bad mechanic (Jun 21, 2006)

timberstone said:


> Go to your local LBS and have them torque a bolt with theirs and see if yours matches. That would tell you if yours is toast or not.


Doesn't really work. Static friction will make a bolt harder to start turning, therefore making the apparent torque higher.


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## mechBgon (Jan 28, 2007)

jeffscott said:


> So do what I say not what I do....hmmmmm


It's your money, so take your pick. I think most folks would be better off with a tough, inexpensive beam-type wrench, which leaves more money for beer :thumbsup: but if you prefer to go high-dollar, Sears has some of the Precision Instruments dial-type for around $150 apiece, so that's $300 for a 0-150 and a 0-600 in-lb to cover your usual bike parts. Like a beam-type, the dial-type give real-time readout of the torque you're currently applying, and obviously they do not require setting and re-zeroing, but I wouldn't feel great about bashing them around or dropping them.

Of the clicker types, the only one I really like is the PI split-beam clickers, such as my Snap-On-badged TQFR50, which do NOT need to be zeroed out after use, are tough, accurate, and very quick to set. However, they don't come in a low-torque range like a 0-150 in-lb, and only torque clockwise, requiring creative use of a crowfoot or other adaptations to torque reverse-thread stuff.


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## jeffscott (May 10, 2006)

bad mechanic said:


> Doesn't really work. Static friction will make a bolt harder to start turning, therefore making the apparent torque higher.


Chances are the LBS one is just as ****ed as yours.......

Easy way to check is use a scale and a lever arm dead easy to set-up with a a normal set of sockets...


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## resonance4x4 (Mar 7, 2010)

You're only going to work harden steel if you exceed it's elastic limit and go into it's plastic range, repeatedly. The only way this is going to happen is if the wrench is abused and used to torque or un-torque a fastener well beyond the wrench's range. By the way, torque wrenches should never be used to unscrew anything.


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## PissedOffCil (Oct 18, 2007)

resonance4x4 said:


> You're only going to work harden steel if you exceed it's elastic limit and go into it's plastic range, repeatedly. The only way this is going to happen is if the wrench is abused and used to torque or un-torque a fastener well beyond the wrench's range. By the way, torque wrenches should never be used to unscrew anything.


Exactly!

OT : Damn jeffscott is really such a loser know-it-all. :nono:


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## jeffscott (May 10, 2006)

PissedOffCil said:


> Exactly!
> 
> OT : Damn jeffscott is really such a loser know-it-all. :nono:


idiot work hardening and changes in the properties of steel most certainly do occur below the elastic limit....

Think it through ever had a spring wear out...yup there you go...


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## bad mechanic (Jun 21, 2006)

I don't think metal will work harden until it undergoes plastic deformation.

http://en.wikipedia.org/wiki/Work_hardening#Elastic_and_plastic_deformation


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## jeffscott (May 10, 2006)

bad mechanic said:


> I don't think metal will work harden until it undergoes plastic deformation.
> 
> http://en.wikipedia.org/wiki/Work_hardening


the plastic deformation occurs in a thin layer on the surface of the member the entire rod is not hardened just the outside layer.

So why do springs wear out then, cause that is what this thing is...a spring.


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## resonance4x4 (Mar 7, 2010)

If the outer layer has plastically deformed, then by definition the elastic limit has been exceeded and the widget has gone into the plastic region. A beam style torque wrench is no where near the yield stress if it's kept within its torque range. 

Springs "wear out" because they experience creep through prolonged and continuous stress. However, the material property does not change. 

Generally, when springs "wear out" people tend to think they get weaker, not stronger.


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## BumpityBump (Mar 9, 2008)

dstelk said:


> I've always wrenched on bikes by feel, but for a few reasons, am now going to use a torque wrench when applicable. I picked up the Craftsman inch/lb microtorque at Sears, on sale (25-250 in/lb range). Par for the course, I started researching things after I made the purchase and now see very mixed reviews. Also, I stinkin' dropped the thing on the tile floor the second I cut the bands on the packaging. I'm wondering if I should just start over, take it back, and get a couple beam styles (one for low torque and one for higher) for basically the same price as the $59 that I paid for the Craftsman. Or, am I just being paranoid and have a nice new additon to the tool quiver that can take at least one drop early on in its service life and still serve its purpose long term???? I hate to think that Craftsman would put out a product that's so horrible that 1 drop would render it useless, but I guess stranger things have happened.


Just use the thing. I doubt the drop hurt it, and the Craftsman is the same wrench sold by Park Tools (or was at one point). I have a Craftsman; it was reasonably priced and gets the job done.


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## vwcalbug (Apr 22, 2008)

As an aircraft mechanic...running a torque wrench all the way down (below the lowest number) and dropping them TECHNICALLY renders them uncalibrated. For home use...you're probably fine. Like it has been said, better then no torque wrench at all. The accuracy on most torque wrenches can be kinda high. If your really worried about it, get it calibrated, but for the home use the craftsman will suite your needs...

THIS is what I own, but I doubt anyone wants to spend $400 on a bicycle torque wrench, although it totally kicks ass as it RECALIBRATES itself on power up because it uses strain gauges, and does the conversions from in lb to ft lb to newton meters
http://buy1.snapon.com/catalog/item...group_ID=17226&store=snapon-store&dir=catalog


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## 4JawChuck (Dec 1, 2008)

Wow another thread of nearly useless torque wrench information, except for a few who have posted I would imagine none of you have ever seen a torque wrench calibrated or even what it entails.

First off, dropping your torque wrench...unless it damaged the housing...is unlikely to have damaged the preload spring housed inside the body that determines the torque value it breaks-away at. The device inside a clicker style torque wrench is a simple overcenter mechanism that is quite durable, you would have to dent the tube or bend the wrench end to affect its calibration. I have calibrated dozens of torque wrenches over the years and the only ones that failed was from wear on the overcenter mechanism which made them unrepeatable from one application to the next or the outer marking tube needed adjustment because the spring was slowly becoming compressed from being left at one setting for long periods of time (measured in years!).

Next...beam style wrenches do not wear out, they are either non-repairable from the beam socket coming loose or damaged beyond economical repair. The idea that the beam "spring" hardens up or loses its "spring" is ridiculous, the amount of cycles it would take to wear one out would be measured in the millions of cycles.

Honestly, if you don't know what the heck your talking about or have any experience doing this kind of thing...stop spreading misinformation! Of the dozens (maybe hundreds) of wrenches I have calibrated or checked 97% were in perfect operating condition. Most people came to make sure they were still working properly and would repeat, some needed cleaning and lubricating because they got dirty inside (clicker style) or the beam got bent because something heavy fell on it. I had quite a few clicker style wrenches that had a tube dent that made it hard to adjust but it did not affect the spring inside since the inner spring tube is of much heavier construction. Many of the wrenches I repaired fell into a can of oil or similar and needed simple cleaning and relubrication.

Of the 12 or so I ended up throwing away, it was from the clicker mechanism becoming worn and not repeating or the clickers outer adjusting tube was damaged so badly you could not adjust the wrench across its range. I think I threw away a few beams for being bent from drop damage...they still worked fine however just not acceptable for production use. Bending the indicator pin on a beam wrench does not damage them...thats how they are adjusted!

BTW the clicker style wrenches that were worn out that I threw away had been in constant use for a few years, mostly they were the larger 50-250ft/pd style that got worn out although there were a couple of inch/pound wrenches in there...all were clicker style because beams are for intemittent use not production because of simplicity and ease of use. These wrenches were used on an assembly line for rebuilding automotive engines in an authorized Ford Engine remanufacturer, the head bolt torque wrenches likely torqued thousands of bolts a day so they were cleaned and checked every 3 months...they typically lasted 2-3 years of three shifts 24 hrs a day constant usage. BTW many of them were Craftsman clicker style wrenches since they were inexpensive and worked as well as the Snap-On or other more expensive mfg's.

I seriously doubt any casual bike rider ever torques more than 50 bolts a years...which means as long as you take care of your torque wrench it will easily last the rest of your life if you keep it clean and dry. Use your common sense, if these things were so unreliable every store that sold them would have recalibration facilities on-site to take your money...the test fixtures are not that expensive.

Most damage I see from casual users of torque wrenches was from corrosion causing sticking in the clicker mechanism or the torque indicating plate becomes dislodged from the beam style wrenches or the plastic floater handle was broken, keep them clean and dry and don't drop heavy crap on it and don't store your clicker style wrench adjusted to a torque value...stop worrying about the accuracy of a high carbon spring that sees less than a thousand bending cycles in its life.

BTW vwcalbug is right...technically any torque wrench that is dropped is uncalibrated but I'll say it again...use your common sense...if it has no external damage and works as advertised and the clicker style wrenches outer tube rotates smoothly its unlikely there is anything wrong with it, they are not made of glass.


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## jeffscott (May 10, 2006)

resonance4x4 said:


> If the outer layer has plastically deformed, then by definition the elastic limit has been exceeded and the widget has gone into the plastic region. A beam style torque wrench is no where near the yield stress if it's kept within its torque range.
> 
> Springs "wear out" because they experience creep Creep is a strictly high temp phenomthrough prolonged and continuous stress. Once they experience this and sag then the number of active coils reduces thus reducing the spring rate. However, the material property does not change. Remember people were saying just bend the indicator back to zero
> 
> Generally, when springs "wear out" people tend to think they get weaker, not stronger.


Springs can get stronger or weaker depending on the situation....

Springs tend to operate at high stress levels since the strain is usually quite high as well...

That leads to plastic deformation that appears as "sag" that doesn't mean the thing is stronger or weaker just deformed.


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## jeffscott (May 10, 2006)

4JawChuck said:


> Wow another thread of nearly useless torque wrench information, except for a few who have posted I would imagine none of you have ever seen a torque wrench calibrated or even what it entails.
> 
> First off, dropping your torque wrench...unless it damaged the housing...is unlikely to have damaged the preload spring housed inside the body that determines the torque value it breaks-away at. The device inside a clicker style torque wrench is a simple overcenter mechanism that is quite durable, you would have to dent the tube or bend the wrench end to affect its calibration. I have calibrated dozens of torque wrenches over the years and the only ones that failed was from wear on the overcenter mechanism which made them unrepeatable from one application to the next or the outer marking tube needed adjustment because the spring was slowly becoming compressed from being left at one setting for long periods of time (measured in years!).
> 
> ...


yup just keep using it, however if you operate it near its capacity it will wear out.


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## resonance4x4 (Mar 7, 2010)

jeffscott said:


> Springs can get stronger or weaker depending on the situation....
> 
> Springs tend to operate at high stress levels since the strain is usually quite high as well...
> 
> That leads to plastic deformation that appears as "sag" that doesn't mean the thing is stronger or weaker just deformed.


I hesitate to address each of these because it will only throw us off the track further from the original question: will a beam style torque wrench work harden over time?

Given:
Work hardening does not occur unless the steel has exceeded the yield stress

Assumptions:
The beam is some type of spring steel
The diameter of the beam is about 3/8"

Let's take a 160 in-lb beam style TW. We don't know what kind of steel it is, but lets say it's spring steel conforming to ASTM A229. It has a yield strength of 71.1ksi (piano wire has a yield strength of 231 ksi, amazingly enough).

MC/I at 160in-lb is 31 ksi. That's a safety factor of 2.3, no where near the yield point.

So again, as long as the TW is used in within it's range, it will never strain harden.

If you'd like to continue this, let's go to PM's. I think the peanut gallery is growing tired of this nerd talk. To the peanut gallery, this discussion is only useless to those who don't understand it. To those of us who do understand it, these discussions are both entertaining and valuable.


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## Bikinfoolferlife (Feb 3, 2004)

resonance4x4 said:


> If you'd like to continue this, let's go to PM's. I think the peanut gallery is growing tired of this nerd talk. To the peanut gallery, this discussion is only useless to those who don't understand it. To those of us who do understand it, these discussions are both entertaining and valuable.


Please keep it here, I won't pretend to understand all of it, but it's still very interesting (why I subscribed a while back). Would like to see it become a sticky with all the good info on torque wrenches in any case. Besides, only us bike nerds use this site anyways...


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## jeffscott (May 10, 2006)

resonance4x4 said:


> I hesitate to address each of these because it will only throw us off the track further from the original question: will a beam style torque wrench work harden over time?
> 
> Given:
> Work hardening does not occur unless the steel has exceeded the yield stress
> ...


Calcs look okay but you did not include the shear at the connection point....

and then resolve the principle to principle stresses...

Also 160 inlbs is 13.3 ftlbs..seems low for a 3/8 inch OD beam wrench...

Point is look at the diameter of a torque wrench beam, and compare that to a well designed socket wrench of the same drive size, the torque wrench has a much smaller diameter....

Also we know that torque wrenchs are "re-calibrated" by bending the needle (see park tool)....So why did the thing bend in the first place....over stressed.

They operate very close to elastic limit....

When at full torque load....so yeah won't work harden at low loads..


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## resonance4x4 (Mar 7, 2010)

Bikinfoolferlife said:


> Please keep it here, I won't pretend to understand all of it, but it's still very interesting (why I subscribed a while back). Would like to see it become a sticky with all the good info on torque wrenches in any case. Besides, only us bike nerds use this site anyways...


Thanks for the reassurance. It's nice to see others are interested in things beyond everyday practicality. I do thoroughly enjoy these types of discussions.


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## resonance4x4 (Mar 7, 2010)

jeffscott said:


> Calcs look okay but you did not include the shear at the connection point....
> 
> and then resolve the principle to principle stresses...
> 
> ...


Beam TW need to be recalibrated only after they have been abused, like using it as a breaker bar. Or maybe the needle got bent when dropped.

I suppose at this point, the only way to settle this is to get an actual beam TW and measure everything and do the calcs. But, we still don't know what kind of material it is.


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