Which Torque Wrench.

[parrish]

Im needing to buy a 'Torque wrench'
Most of my sockets are 1/2 inch drive.
The choice of available wrenches and ranges of torque are vast.
I need a calibrated wrench to cover all the applications during an engine rebuild.
Can i ask what you are all using and any recomendations, does and donts etc.
Steve

[DeltaDave]

Its not about your socket size that will depict what torque wrench you need. You need to decide what torque range you require. Usually a 3/8 drive is adequate for most fasteners on an engine however you made need to go up to a half inch drive for head bolts/studs. I can only advise you on the Snapon range at this moment in time as I am a recent Ex SnapOn dealer.

QD1RN25 1/4" Drive 50-250 dN•m which is 5 - 25 Nm cam caps and small fasteners
QD2RN100 3/8" Drive 20-100 N•m Generally 80% of other Fasteners on Engine
QD3RN350 1/2" Drive 70-350 N•m Head Bolts/studs, crank pulleys and larger fasteners

The above 3 are click type torque wrenches, you may want to go digital as they do both Nm, inch/lb, ft/lb, and angles in which case the part numbers are:-
ATECH2FR100A 3/8" drive
ATECH3FR250A 1/2" drive

Please note I cannot supply any longer

[Guy Croft]

Snap-On are 'tops' in my opinion. The digital ones are fabulously accurate but you need a big supply of Duracell batteries!

G

[DeltaDave]

The newer versions (grey colour handle) no longer have battery issues, the red handle ones had issues with just entering a standby mode rather than switching off therefore draining the batteries. The grey ones also do angles which is very impressive.

Snap-On are 'tops' in my opinion. The digital ones are fabulously accurate but you need a big supply of Duracell batteries!

G

[Guy Croft]

Ex Snap-On..

What you doing now Dave?

G

[DeltaDave]

Still collecting the remainder of the outstanding money owed to me for the short term. Not sure what direction i'm going in at the moment, might take on a couple of resteration projects along side selling off the remainder of my stock and other items. I need a holiday really to blow away the cobwebs, might go to Italy for a week in the spring to see all the car museums.

[tricky]

Steve, I'm a big fan of britool torque wrenches, they are priced reasonably and very well renowned as a well made and highly acurate unit.

My favorite type is the ones with the 'break back' or 'snap' back mechanisim, this gives you a really progressive feel as you come close to the set point when torquing up a fastner. It also offers a nice visual indication of when it is about to click off, so you don't get caught out.

If you don't know the type I mean, I can take a picture of one for you.

Or

Google "Cromwell tools" for a britool stockist.

[parrish]

OK bought myself a 'TOPTUL'
happy with it, came with inspection and calibration certificate.
Steve

[WhizzMan]

Regardless of what brand you buy, buy one that has the torque range you have to adjust "in the middle". The end of the scale (both sides) is where torque wrenches tend to be not very accurate. This will mean you need at least two, possibly even three wrenches if you work on modern engines and want to do it "by the book". I've seen people break valve covers on Alfa romeo 16V TS engines because they didn't have a 1/4 torque wrench and thought they could "feel" how much torque the bolts needed. The amount of thread repairs required on heads and other aluminum parts quickly becomes more expensive than purchasing the proper tools. Don't skimp on good tools, you'll save the money in repairs you'll have to do again, if you work on cars more often than your own restoration.

Several brands buy from the same manufacturing plants. Some have custom runs done with special quality requirements, but often, you can buy the same wrench with only the brand name and type number that's different. Often, the quality brand name will be much more expensive than the "generic" wrench. It's worth spending some time investigating.

When purchasing second hand, be aware that these tools wear out and my need re-certification/calibration. Often, money saved on purchase is more than lost on getting the tool into the shape required to do the job properly.

[Guy Croft]

.. and never 'test' the 'click' of a torque wrench but clamping the drive in a vice.

Vices and bolts don't behave the same, see..

G

[tricky]

Don't skimp on good tools, you'll save the money in repairs you'll have to do again.

I agree 110 % with that, I already had a nice 1/2" 30 - 120 lb/ft britool wrench and wanted another small 1/4 drive tool for the lower range. I thought to my self "oh it's only a baby one- I'l buy a cheapo" and it subseqently stripped some camshaft cap threads on the first outing. Never again.

[Brit01]

+1

I have a large 20 kg-m torque wrench (1/2") and it's pretty useless for any torque below 3 kg-m I would say.

I have one stripped thread on my alloy head but luckily it's only a small supporting bolt in between the large 6 head bolts. Once the head bolts are on they don't have much function.

have to get myself a small 3/8 or 1/4 wrench some time with smaller increments.

Chris

[turbofiat]

One problem I have had when it comes to torque wrenches is finding one that goes as low as 20 inch lbs.

I rebuilt a T3 and the compressor nut requires 20 inch lbs of torque. Since this isn't something I do everyday I decided to borrow a torque wrench from a mechanic at work. Trouble is the one he had, the lowest setting was 50 in lbs. So I decided to check with another mechanic. Once again the lowest his wrench when to was 50 inch lbs. I think both of these were made by Sears Craftsman. I don't know if Snap-On makes one that goes lower or not.

I know this isn't something you should do but out of nessessity I had to guess. I applied Lock-tite to the threads then just snugged the nut down to where the compressor spins freely with little resistance as possible but has no play in the shaft being careful not to put too much pressure on the compressor wheel. 1500 miles and so far the turbo is still doing well.

[Nobby]

A few weeks ago I searched the internet for 'How tight is hand tight' and came up with some interesting results. I'm always scared of breaking bolts or doing things up too tight if I haven't got the right tools.

According to NASA, the mean maximum torque strength of a male is 13.73Nm through twisting your arm (right hand) to the right (supination), or 17.39 Nm to the left (pronation). There are figures for finger strength too, but measured by Force not Torque.

Happy to post the link if Guy okays it.

Or perhaps I need to just get out more.

[Guy Croft]

The human arm applies force not torque.

The torque the arm is capable of applying depends on the length of the lever to which the force is applied. To that extent the ability of the human arm to apply torque is almost unlimited.

We should both get out more, in the meantime post the link here!

G