I've got a birthday coming up and I'm thinking of asking for a torque wrench. Is there anything I need to know about choosing one, or will any one from a big hardware store be OK?

Thanks

Buy a good one.

Get a clicker, not a pointer and scale type.

Name brand is **usually** better.

Go to the biggest tool supply shop and see what they have got. Some tool vans are cheaper, some dearer.

Get it calibrated.

store it unwound where it wont get knocked by other tools etc.

Get shown how to use one by someone who knows how to.

You will then use it to fix your great grand kiddies cars.

You will look at it...You will love it.. you will want to sleep with it... (wrong list???)

My $0.02c inc gst


A cheapo torque wrench is mostly useless.

i dont have the numbers on me but a lot of VW settings are quite low. 15's and 20's and 25's foot lbs?

I remember when i was building my motor the torque wrench i borrowed was a real good "clicker" one but was usually too strong for the settings.
A lot of the required settings were below the minimum

Have a look at a manual as to the settings you need and find a wrench (if they make them) where the settings is in the middle of the scale

hmmm.... can you get a good 3/8" drive rather than a 1/2" ?

[Edited on 19-8-2003 by blue74l]


heh heh had my manual in front of me all the time!!

example

head nuts

torque to 7 ft/lbs
then tighten to 23 ft/lbs

You have a look and see if the wrench can be set at 7!
I remember the minimum was 20 on the one i had

[Edited on 19-8-2003 by blue74l]

as mentioned, get a click type. the needle and scale k-mart type are worth their weight in packing foam.

get a good brand too. I bought a snap on one, and while it was the equivalent cost of the Chinese national debt, it has served me very well all through my trade years and is still serving me well even though its only a hobby for me now.

I will quote the Ajax bolting catalog

"Although torque bears no fixed relationship to fastener tension, the use of torque wrenches is the most common method of pre-load control because of simplicity and relative economy. Many factors, including surface texture (cut or rolled threads), surface coatings/lubrication, thread interference and speed of tightening affect the torque-tension relationship and up to +/- 25% variation in preload has been measured on similar fasteners receiving identical torque. "

So basically even the best torque wrench is only +/-25% accurate. In the engineering world they are rarely used, but on a car you don't have much choice.

Buy a decent brand (not supercheap auto), but don't go silly. The additoinal accuracy gained by more expensive brands doesn't mean much when the best is only 25% accurate anyway. What you want is a brand that will give good accuracy, but mainly is good enough quality that some part of it won't break.

The pointer and scale types can be suprisingly good, as they are also stored in the relaxed state, and the effective spring component will not sag with time. They are also easy to see if they are not calibrated anymore. But I do prefer the clicker.

buy two a little Warren & Brown for upto 20ft/p and a bigger one for when you do work on others cars. I got a repco one years ago (~$300) it does 20~150+ i think and its a clicker. Its made in england which is reassuring. I'd spend whatever i could spare as this is a valuable asset in your tool chest

Thanks for all the info guys, that's given me a good idea of what to look for!

555bug, I was made in England too. Does that reassure you? ;-)

Purple

are you a clicker or a pointer then??? :o

blue

neither any more - my spring has sprung.

Yes, its best to buy from a tool specialist.
Warren & Brown is the same clicker type I have but starts at 20 ft/lb also. If You look at the el cheapos.. they are all at different torques.. on the shelf !!!!
Remember that a Torque wrench can only be used to Tighten nuts & bolts up...
Never Use it to undo... tighten only....
I did My engine with lubricated threads... My Son did his with Dry threads....
Can You Imagine the DIFFERENCE !!!!

So should I always torque with clean lubricated threads? Does ordinary motor oil do the trick for thread lubrication?

Ive had a click type one for about 50 years or so it was my Dads but i have it now

I suggest 3/8" drive and only up to abouyt 60 ftlbs. The smaller scale is the best for VW work.

Yes, Purple Martin,
clean, lightly oiled threads.. Engine oil is OK... Never torque a stud or bolt in One go... and if there are 4 studs etc holding a plate ? onto something... torque each ONE down in 3 or 4 goes... if the total was 15 ft/lbs You could do each one : 5 then 10 then 15 ft/lbs... get the idea.
Actually one of My 9 VW Manuals says to use anti seize on all Steel threads on a VW Engine, including the spark plugs...
because of the differences in the two metals...
The small Torque wrench would be best for VW engine Work....
Lee 68AutoBug (o\!/o)

why shouldn't you UNDO bolts and nuts with a torque wrench? Will that detimentally effect its accuracy? and how does one check the accuracy anyways? using another torque wrench and counter torque-ing and and taking a mean reading?

:tree does anyone actually use this icon?

As Wes has pointed out, the accuracy with which a given torque setting translates into the desired bolt/stud tension is afected by a range of factors, so it's not particularly useful to get worked up about 'accuracy'.

What *is*, however, important and worth paying the extra for is repeatability; that's why I paid $$$ long ago for my Sidchrome clicker. I acknowledge that the head stud tension may well be 10% off from the desired tension (not 25% in this case, because when the torque setting was specified the specifiers knew the exact material, facings etc. that would be encountered), but I really want them all to be within 5% of each other. With a good (clicker) torque wrench and careful oiling, progressive torquing and slow movement, this degree of repeatability can be achieved.

How do you check the repeatability? After torquing a stud to the required setting, set the torque wrench to 5% more; the stud angle should increase before the clicker fires. Then after torquing another stud to the required setting, set the wrench to 5% less and retry, the clicker should fire before there is any change in the stud angle. Thus you can check the repeatability and consistency of your torque wrench/environment/procedures without a second wrench.

HTH

On the brand name thing; I recently used a Kingchrome torque wrench, and it was utter crap, mainly because the micrometer scale didn't line up correctly, making any reading inaccurate. It could have been a one-off, but I doubt it.

I ended up using some American brand that was actually manufactured in Germany. If I could remember the brand, I'd buy one because it looked, felt and worked brilliantly! :thumb

I sortof permatley borrowed my dads good sidchrome one. Its about 30yrs old but it works well.

Freudian slip?? or do you build engines like no one else :bounce

Yes, but You probably use Your Torque wrenches much more than We VW Owners do Ben......
I got My click type Warren & Brown torque
wrench from a local mechanic. I had an extended loan of it, and the mechanic left town... and left the state...
I still have it....

as long as we're using the settings the factory said to use on the parts the factory supplies, 25% is a frikken huge margin for error. I'd hope they understood the relation between the parts better than that. (metal types, thread types, and method of use should be reasonably consistent...) a cruddy torque wrench is still a cruddy torque wrench; if it's accurate +- 20% on a dry, cut thread non standard stud fastened jerkily in one twist.... catch my drift?
i had to replace a head gasket on a mate's CX500, where the bugger had the head tightened to about half what it should be. it lasted about 50 k's. now it's good.:tree
don't drop your torque wrench.
eat your greens.
get that finger out of your ear, you don't know where it's been.

if you want real accurate measurements, you need to use new studs and nuts and washers everytime. I don't think many people will do that. If the nut doesn't go all the way to the washer by your fingers easily, then your torque will be inaccurate by at least that force.

Many newer engines have head studs that are only to be used once, and are to be thrown away each time. They help get more accurate stud tensions.

[Edited on 26-8-2003 by Baja Wes]