I always use a torque wrench where possible and torque settings as per the manual. But not having had formal mechanical training a blonde question? : When the torque setting is given as 22Nm+- 2 what should your decision be 20Nm 22Nm or 24Nm ????
Lazyboy.

22 is the spec. You can go a tiny bit more, but never any less.
I would attempt to get at least 22 + a little towards 23. If you get to 24 you need to loosen & retry.

hi i always read it as 22nm but it can be btween 20 and 24 ( + - 2) . its just there as differnet torque wrenches are callibrated slighty different. With the BMWs always just get the torque that it says first ie 22nm. Hondas are the most nonforgiving theyll strip a thread if you pass by 0.5 . pete not going to give speel that i had to sit and listen for an hourand half in college about spring forces blah blah .

pete

I did not read the information correctly.
He says + - 2.
I read it as +2.
The best you can do is try very hard for the stated spec. If you go over/under by 1 your good.
Sorry for the bad reply

I saw a utube video and he said lower spec if using new crush washers and upper spec if you are reusing the crush washers. Being on utube is has to be true

Caution!!! Although the torque wrench may look the amatears dream they are certainly not. Most wrenches are inaccurate, many aluminium casting are stripped by there misuse. In industry they are checked very regularly against a master instrument by inspection peronel. Never never never, set a wrench to the required load straight off always always work up to the correct value a step at a time if 20nms are required go 7 then 16 and finally 20. If at any time the load feels to high stop and check feel is still important. The advantage of a torque wrench is consistancy which ensure that the load is shared equally by all bolts in the pattern. Ok undertighten and it will possibly come loose but if you over tighten you run the risk stripping threads or worse still weaken the joint by taking the bolt beyond is load perfomance leading to breakages. If you can get it checked if it has been out of the box for any amount of time.

Best of luck

Well said. I agree completely. I usually try to "err" on the lighter side of the spec, especially on this bike.

Thanks All for the good advice.
Lazyboy

Great discussion, the thing with older metals they crystalise, especially aluminium alloys subjected to heating and cooling cycles, expanding and contracting many times.
Great advise about stepped torque up and feel - thats it. Bolt / nut locking technology has come a long way with loctite but I prefer star or spring washers, locking tab washers and wire if essential, especially on all those hidden threads once the machine is assembled. Loctite is fine steel to steel but heat slowly lessens its effect hence tabs are good where called for. Great learning here.
Rick

Just a further point. The convention is for the torque settings to assume that the both threads are dry. Always check that the torque is not supposed with lubricated threads so beware. If you use copper slip or any other anti sieze back of a bit. Dry to oiled can vary by upto 50% and over stress the bolts. Having been apprenticed in the pre loctite era and having gone through the sales hype about loctite my experience is it ain't all it's cracked up to be, use it only as a last resort; tab washers, star and spring washers (only on flat machined surfaces) split pins, nyloc nuts,and wiring are infinitely supperior. On some BMW genuine spares you will see what looks like blue paint now that is a very good thread lock. Hope this is of help.

I have never seen a torque spec that is intended for dry threads.???

ibjman wrote:I have never seen a torque spec that is intended for dry threads.???

 As a retired car mechanic I have:e.g.most wheelnuts/bolts are specified no lube or copperslip. http://www.popularmechanics.com/cars/how-to/repair/torque-wrench-101-how-to-get-the-right-amount-of-force-2 is worth a read. In my experience only bolt stretch measurement gives precise measurement otherwise friction differences(rusty/clean/lubed/dry) only get you somewhere near.

Wasn't there was a problem years ago when the monolever was introduced due to the wheel bolts coming loose because owners greased them.

Hi there, all I could add to this subject is that you should not use the torque wrench with an universal joint extension, unless you have the resources and skills to calculate the real applied torque, this  equals the measured one only when the joint is straight, otherwise will be minor  and it will decrease as the deviation angle increases (reaching cero for 90deg angle) following a fairly complicated formula ,  googleing the subject you'll find detailed explanations.

Best regards

JAP

ibjman wrote:I have never seen a torque spec that is intended for dry threads.???

+10

I was in  a tool shop recently and saw a flexible drive (looked like a short piece of shower hose in that it was a wound construction). Would this transmit the correct torque?

It looked like this


http://www.amazon.co.uk/Clarke-PRO137-Drive-Flexible-Extension/dp/B00BDMWSO0/ref=sr_1_15?s=diy&ie=UTF8&qid=1377455969&sr=1-15&keywords=flexible+drive#productDetails

RicK G wrote:

ibjman wrote:I have never seen a torque spec that is intended for dry threads.???

+10

http://bmwmotorcycletech.info/torquevalues.htm

http://bmwmotorcycletech.info/torquespecs&problems.htm

Reading the above links may enlighten.

ibjman wrote:I have never seen a torque spec that is intended for dry threads.???

Rear wheel bolts are. Always.

I needed to torque a reverse bolt today so anticlockwise. I've got 3 tension wrenches here and none of them work in reverse. Whada ya do

My torque wrenches all allow the square drive to be pushed through the head so that they can be used for left-hand threads.

I don't think I've ever seen one that doesn't (look again Robin).

http://www.ebay.com.au/itm/like/121137423856?showlimghlp=true&lpid=93

Too late for garage stuff, it's 1am   but that's one of them. I don't think the head reverses, maybe it does?

That type of torque wrench only works one way, they are "solid" in reverse i.e, no click. I have two of them here, and out of curiosity I just checked them. I also have one of the type that you push the square drive through on, and of course that works both ways.

They just flog off all the crap no one else will buy down here at twice the price 

What's that switch for?

I reverses the ratchet but none of them click in reverse.

Of course.  

Perhaps the problem is that being upside down, it would be too complicated to make an antipodean one that goes backwards too?

i have always used valvoline  X-ALL grease for Wheel bolts, never had any problems?

MikeP wrote:

ibjman wrote:I have never seen a torque spec that is intended for dry threads.???

Rear wheel bolts are. Always.

k-rider wrote:i have always used valvoline  X-ALL grease for Wheel bolts, never had any problems?

I think that we all do things that are not recommended at times. It doesn't alter what's recommended.

 

Torquewrenches are one of the most abused tools, part of my job [ in the Mil/Air environment ] is that each Torquewrench gets tested every three months the test involves readings taken three times each at minimum 0, 25%, 50%, 75%, and at Maximum over the wrench's range thats fifteen times each wrench.
Each wrench has a minimum and maximum per % test and if it exceeds or does not reach the minimum it is scrapped, fixed range types have to be adjusted to the given setting and locked.

Before use the airman [women] has to sign for using the wrench and has to test it against the value they need and register its number on the job card, We spend a lot of time educating people how to use these peices of test equipment and how they should not be used for breaker bars ect and most important is that adjustable types SHOULD ALWAYS be unwound after use otherwise it weakens the spring.

A respectable garage should hold a Torque tester meter so maybe they could test them for you, and if you look on the manufacturers webb site like NORBAR it has all the info required to look after them and also has the test charts for working out conversions with adaptors and measurements.


BIG D

 
Should anyone be interested, lifted from Norbar info on bolts and torque

Anyone tried the torque wrench from Motobins?

I've always wondered about the effect of using a small extension socket bar to get into tight places. Does this
add or detract from the correct torque when tightening?. Anyone care to guess?.
Tks, RT

Hi there, as long as the extension is straight and doesn't changes the angle, it would not affect the torque.
Best regards
JAP

But examine the extension very carefully and if you find the small letters "Made in China" add
20% torque for every 10 cm extension lenght.

Inge K. wrote:But examine the extension very carefully and if you find the small letters "Made in China" add
20% torque for every 10 cm extension lenght.

Hi Inge, I´m sorry I don´t understand, why to increase the torque?
Best regards
JAP

Did you read the small letters?   ...........or have used cheap Chinese tools?

Inge K. wrote:Did you read the small letters?   ...........or used cheap Chinese tools?

Sorry, the small letters didn't show in my screen, now I see "made in china", but I think that the extension wont change the reading, it may twist but as long as it stays straight the measured torque should be the applied one.
Best regards
JAP

From time to time I ain't that serious..........especially on a late Saturday/early Sunday
................it was primary meant as a joke.

Well, you got me   
Now you can say BAZINGA  
Best regards
JAP

Inge K. wrote:From time to time I ain't that serious..........especially on a late Saturday/early Sunday

   

japuentes wrote:Now you can say BAZINGA  

     

Back in 70s when I was a Mech. I remember SnapOn selling an ext. set for impact guns. Each extension would equal a diff. torque value when installing lug nuts on wheels. I never bought a set. I could not understand how these could be used on different guns from diff. manufact.
But I do feel the value of torque will be changed with a long extension added to a torque wrench.
Ok, let the bashing commence 

frogy wrote:Back in 70s when I was a Mech. I remember SnapOn selling an ext. set for impact guns. Each extension would equal a diff. torque value when installing lug nuts on wheels. I never bought a set. I could not understand how these could be used on different guns from diff. manufact.
But I do feel the value of torque will be changed with a long extension added to a torque wrench.
Ok, let the bashing commence 

Hi there, I´m afraid that your feelings are not shared by physics.
A straight, static, shaft supported only at both ends, with a torque applied at one end will have the same torque in opposite direction at the other end, because for it to be static the sum of moments has to be zero, and that is a physics law.
My guess is that the confusion begins with a method for tightening bolts known as the "final rotation method" on which you reach the final torque by rotating the head of the bolt a specified angle (usually 90º) if you do that with an extension and measures the rotation at the distal end (not at the bolt) you'll need to consider the torsional deformation of the extension´s shaft and ad it to the target angle in order to reach it, but the torque will be the same.
Or not...
Hope this helps.
Best regards
JAP

The extensions Frogy have in mind is to be used only together with a impact gun.

When the predetermined torque is reached the extension start to flex,
you can let the impact gun just hammer...the extension will just flex and
not transfer more torque to the bolt/nut.

ALDI have this TORQUE WRENCH for sale this weekend. I know there are different types but any thought about this one?
Would it be worthwhile purchasing?
Is there any way of testing to see if its delivering the correct torque?

Only $25... and they have a 30 day returns policy. Can't go wrong really.

Yeah they are OK middle of the range bur before you use it try it against a high quality one as they do vary a lot, just so you know to set high or a bit low to compensate.
I have a full set of Warren and Brown but not everybody wants to spend $1700 on 4 wrenches.

In the mid seventies, working in a motor factors that sold tools, I was persuaded to buy a 'Proto'  1/2" sq drive torque wrench. It cost me nearly a weeks wages then (£12.75) but it came with a lifetime guarantee.
I still use it to this day and always set it to the exact torque setting specified, on the basis that the quoted percentile error allows for differing manufacturing tolerances between wrenches. I have always used the step up tightening method on things like cylinder heads because that is what is advised by the manufacturer but in truth, very little else. I don't think I have ever stripped a thread or had one loosen whilst using this torque wrench, despite owning a fair few Hondas . I've always taken care of it and released the tension after use.

I recently had occasion to buy a 1/4" square drive torque wrench made by Draper and as my Proto has never been tested I had a little trial (unscientific) over a range of torque settings. Using one then the other to tighten a nut and bolt then setting the other torque wrench to the same value to see if it tightened any further or if I could significantly reduce the indicated setting to achieve the same tightness.

From the lowest setting of 10Nm's up to about to about 17-18, the Draper suggested that the Proto was slightly over-tightening and vice-versa. But I got absolutely no difference from 20nm's up to 70Nm's (the Draper has a max setting of 80Nm's).

Now whether or not I am actually achieving the pre-set torque on either wrench is a matter of opinion but I agree with Eastern-phoenix in that for the price that the average shed mechanic is paying, they provide consistency rather than absolute accuracy.

I did something similar recently. I bought a half-inch drive Norbar around thirty years ago and in the last couple of years I'd been getting a bit twitchy about its accuracy after all this time. There's no way can I afford to get it calibrated 'professionally' (it would be cheaper to buy another one), so I went the other route and did buy another Norbar but with a different range (starts higher, goes higher). I then went for the same tighten-and-cross-reference sequence as Fentible did and found that there was no difference over the entire overlap range. So they're either both accurate or both out by the same percentage.

Torque is cheap...

I picked up Harbor Freight's 1/2" torque wrench priced at $22.00 (USD). HF is a hit or miss proposition, being a made-in-China clearing house, yet I'm convinced it's a bargain. I've bench tested it side by side with far more expensive counterparts in the machining dept. where I work and it has - so far - proved accurate after over 2 years from purchase. Apparently its manufactured in Taiwan. 

Car Craft Magazine's review: "We frankly didn't expect this little unit to be very accurate. But testing proved otherwise."

Also from the article:
"...inaccuracy occurs because the internal spring loses its tension, allowing the wrench to break away (click) at a lower torque value. [T]his is a common problem for all types of clicker torque wrenches. The point here is that you should always return your clicker torque wrench to the base setting before storing the wrench. This simple step will maintain the wrench’s accuracy for years instead of mere months."