Halfords Torque Wrench

[andrew34ruby]

I don’t use a torque wrench as there are to many variables  I just find that the correct size spanner has a length to tighten the nut/studs correctly. That’s why spanner’s have different length to suit the size of nut they fit. 
If you use nylock nuts for your big end caps you can’t use a torque  wrench unless there is some way I don’t know about.    I will add that I don’t go in for competitions or racing my Seven.

John Mason.

I don't use a torque wrench either John. Never have done.

[Zetomagneto]

Andrew, you put a flat washer under the nut, which exposes more hexagon.

[andrew34ruby]

Andrew, you put a flat washer under the nut, which exposes more hexagon.

Do I?

[Bob Culver]

The comments about spanner length very apt. Tendency now is to use a ratchet set with one length for all. Should be gripped corrsponding the appropriate spanner.
Many now have no experience of bicycles, old bomb cars etc so have built up no feel.
The bendy bar ones are perfectly adequate and calibration can be checked with weights.
Anyone who has tinkered with moderns gets a whole wrong impression of tensions. Everything is done up absurdly tight. 
There is a huge difference between the mild steel of everyday hardware bolts, hardware HT and equivalent, and the fancy grades beyond up to the more exotic Allen head setscrews. I doubtif many original parts much exceeded hardware ht grade, or need to. 
It is helpful to read up on torsion wrenches and use of as the variables  (oil, grease, washers etc ) are huge.
By practising on scrap in the vice you can calibrate yourself and spanners, and learn the limits of various grade fasteners. 
Torsion wrenches are helpful in awkward positions when hard to judge otherwise.

[Chris KC]

Bob is quite right that numerous variables are at play, especially when it comes to worn components, and the presence or absence or lubricants. The way the wrench is used can also lead to variation in results. That said, a decent torque wrench used properly will give consistent and repeatable results, which is distinctly beneficial for certain parts of the car. For sure some mechanics can do that by feel, but many can't, and even the best have off days.

On the topic of modern cars Bob I'm not sure I'd use the word 'absurdly'. Critical bolted joints are nowadays individually tested on a number of samples, the results analysed statistically, and the torque range specified to guarantee the joint against yield or loosening. They are mostly designed to remain done up for the life of the car. I'm inclined to agree with anyone who thinks the quality of modern general purpose automotive bolts could be better, but the torques are generally about right and that's why you rarely find a mechanic these days going around the car with a spanner nipping things up tight.

[Jamie]

Hi Jamie
A lot of people manage to rename me Chris, so I'm assuming your query is directed at me!

Whoops. Sorry. That is what comes from using a phone with a small screen and not reading carefully.

Thank you for the information about your experience with the Halfords tool, which does rather put me off. So far, I have returned a US Pro wrench (thimble jammed solid half-way up every time), Teng (thimble action rough and felt like it was full of sand and the imperial reading and the metric reading at the same setting were a long way of agreement) and a Draper unit (smooth action and clear markings, but scale progressively less accurate as it increases. Seemed to be about 6lbs out even at 10lbs setting).

I shall look for a Britool or a NorBar.

Thank you.

Jamie.

[Steve Jones]

I've two Norbar 'click' type torque wrenches. one, 3/8" drive, 5 - 40 lbf/ 8 - 54 Nm and one 1/2" drive, 30 - 150 lbf/40 - 200 Nm. Both obtained second hand from known sources. The small wrench does just about everything on an Austin 7 and I've lost count of how many big end and cylinder head nuts it's been used on. Never had any problem when tightening Nyloc big end nuts. You just need a thin wall socket. The big wrench does have the odd use but is more useful on things like wheel bolts on our motorhome and the like.

Both have an easy action and adjustment, scales that are easy to read in both imperial and metric and feel 'quality'.

Steve

["Slack Alice" Simon]

Trying the Norbar for the first time I was interested in the variation in torques that I had previously put into the 14 head nuts with my short ring spanner.

Not that the Norbar is neccessarily right, but it feels right, and I know I am probably not accurate, so rightly or wrongly, I am happier with the result.

[A G Wood]

Norbar are quality Steve. Having exchanged a week's apprentice wages for it in the 1970s, my 1/2 drive one has done sterling service in a professional environment until quite recently. I used to get it checked annually when the mobile calibration guy called in to test and re-certify the workshop torque wrenches [yearly certs for torque wrenches were part of the vehicle franchise agreement] and it always tested within spec. both for accuracy and repeatability. The only issue I ever had was the original plastic 'micrometer adjustment' knob cracked after about 10 years... Always slacken the setting back to zero after use, and do a couple of dry fires [holding the square drive in your bench vice jaws] before using it, if its been idle for an extended period was the advice I was given.
Agree with the Jamie's comments about the rough thimble action of the Teng brand wrenches, also if they are the ratchet head variety, regrettably the ratchet has/had a very short service life before it turned the wrench into a knuckle buster.
And yes, you will seldom see a mechanic nipping things up nowadays. The only ones we really used to check, apart from drain plugs, level plugs and road wheel fastenings were the handful of split pinned ones on the steering linkage of one particular locally assembled product where the assembly monkeys would sometimes hand tighten the castle nuts, fit and spread the split pin then smear the nut with the 'I've torqued this to spec boss' paint.

[Bob Culver]

Hi Chris

My wording was a bit general. The internal bolts stressed by the very high cyl pressures and revs are critically tightend. But everything seems to be incredibly tight. Anyone transferring similar to Sevens will leave a trail of stripped threads.