Torque wrench choice

S

syvictoria

Well-Known Member
Joined
12 Oct 2009
Messages
1,888
Location
Europe
Visit site
Sorry, I know that this has been discussed in the past, but I'm looking for recommendations for a torque wrench for general ongoing maintenance duties, and having never used one before, I'm struggling to know what exactly I'm looking for!

I've spotted this one, which seems to offer a good range at a reasonable price:

http://www.amazon.co.uk/gp/product/B000ROF64O/ref=gno_cart_title_1?ie=UTF8&psc=1&smid=A327GSNL65G6Q2

Is a ±4% accuracy good, bad or indifferent? Is there any reason that I shouldn't purchase this one? Should I invest in something that covers the 4-25nm sort of range too - will I need this often in the normal course of ongoing maintenance (Beta 25 diesel, etc.)?

As always, TIA!
 
syvictoria,

I couldn't make out from the link if that wrench does it, but I'd go for the type where one sets the torque loading and the thing stops ( goes free ) at that amount of pull.
 
Seajet said:
syvictoria,

I couldn't make out from the link if that wrench does it, but I'd go for the type where one sets the torque loading and the thing stops ( goes free ) at that amount of pull.
Click to expand...

It will momentarily stop at the set torque. Similar torque wrenches at tool station and screwfix about £31. You are probably not going to use it much, unless you intend rebuilding the engine.
 
I'm not sure a 3/8 drive is the best choice. The one I've had for years is 1/2" drive. It 'clicks' when you get to the correct torque. The only problem with mine is that it doesn't do very low torque settings, but it's never been a obstacle to any engine rebuilds I've done.
 
Small bolts and nuts needing low torque settings shouldn't be a problem if you use common sense when tightening them with a well-fitting spanner.
I would agree that a 1/2" drive would be better for higher torque settings. It's when you are setting higher figures that your "feel" is of little use. Can you tell the difference between 70 lb/ft and 90 lb/ft by feel?
I wouldn't think 4% is particularly accurate. I have an ancient Britool wrench which hadn't been calibrated for years. A friend was manager at a workshop tool manufacturers tested it and it was outside their 2% margin. He lubricated the washers in the head mechanism and it tested inside the 2% range.

Click-stop are best, in my opinion.

However I wouldn't spend that much on one today http://www.tool-net.co.uk/p-378391/britool-evt1200a.html?gclid=COvbkN-L77oCFTLJtAodxR8A-A
 
Last edited:
syvictoria said:
Sorry, I know that this has been discussed in the past, but I'm looking for recommendations for a torque wrench for general ongoing maintenance duties, and having never used one before, I'm struggling to know what exactly I'm looking for!

I've spotted this one, which seems to offer a good range at a reasonable price:

http://www.amazon.co.uk/gp/product/B000ROF64O/ref=gno_cart_title_1?ie=UTF8&psc=1&smid=A327GSNL65G6Q2

Is a ±4% accuracy good, bad or indifferent? Is there any reason that I shouldn't purchase this one? Should I invest in something that covers the 4-25nm sort of range too - will I need this often in the normal course of ongoing maintenance (Beta 25 diesel, etc.)?

As always, TIA!
Click to expand...

There are two main types of torque wrench, the one with a dial on it that you pull on until the needle indicates the desired torque, or the break-bar type - the one you are looking at.

Back in the mists of time when I made engines accurate tightening of nuts and bolts was a work in progress, after lots of experimentation it was decided that the norbar (break bar) wrenches were the best in terms of most accurate and most consistent.

To test a torque wrench you load up oiled nut with a bar of known length and weight of known mass at a known length from the centre of the nut - so you can calculate the moment and hence the torque, you then set the wrench you are testing to that torque and see what happens when you try and tighten the nut - it should click. It will be appreciated that there are many variables not least the standard of fit between the nut and the thread its running on.

The one you have suggested is a bit limiting, I would suggest the next size up (18") as it will be much easier to use and be able to cope with most of the bolts on your boat including the propeller (probably).
 
john_morris_uk said:
I'm not sure a 3/8 drive is the best choice. The one I've had for years is 1/2" drive. It 'clicks' when you get to the correct torque. The only problem with mine is that it doesn't do very low torque settings, but it's never been a obstacle to any engine rebuilds I've done.
Click to expand...

I am an unashamed torque wrench snob: Norbar or nothing. That's the definitive "set the torque, turn till it clicks" variety. My standard one is a 1/2" drive SL1, but when I replaced the head on the 1GM10 I added a 3/8" drive SL0 because some of the torques are both low and critical - in particular the exhaust elbow securing nuts. The SL0 has the additional advantage of fitting in a small toolbox, though it only goes up to 20Nm.

I bought my SL1 new but got the SL0 on eBay where they come up regularly for thirty quid or so.
 
Marsupial said:
Back in the mists of time when I made engines accurate tightening of nuts and bolts was a work in progress, after lots of experimentation it was decided that the norbar (break bar) wrenches were the best in terms of most accurate and most consistent.
Click to expand...

They are particularly good when you are doing sequential tightening of, for example, head bolts. Set first stage toque, clickety-clickety-clickety, set second stage torque, clickety-clickety-clickety and so on. Fast, easy, accurate.

The worst thing I have ever had to undo/redu was the front hub nut on a 2CV, which from memory is 240Nm. 3/4" drive socket, breaker bar, six feet of scaffold pipe, jump.
 
Seajet said:
syvictoria,

I couldn't make out from the link if that wrench does it, but I'd go for the type where one sets the torque loading and the thing stops ( goes free ) at that amount of pull.
Click to expand...

Goes free? That sounds like it should be good for skinning knuckles/smashing teeth out/falling off hop-ups.
 
Note that the one advertised is described as Sealey style.

Sealey = marginal quality. Sealey style = who knows how bad.

Edit: The full text suggests it is a Sealey branded item. Peculiar wording in the title if it is, but adequate for occasional use if so.
 
Last edited:
After a bit of asking around various types of aircraft engineers I bought one of the Halfords Pro range, which was then tested and found to be exactly what it's certificate said. Their 3/8" had a better than average upper range too.
 
JumbleDuck said:
I am an unashamed torque wrench snob: Norbar or nothing. That's the definitive "set the torque, turn till it clicks" variety. My standard one is a 1/2" drive SL1, but when I replaced the head on the 1GM10 I added a 3/8" drive SL0 because some of the torques are both low and critical - in particular the exhaust elbow securing nuts. The SL0 has the additional advantage of fitting in a small toolbox, though it only goes up to 20Nm.

I bought my SL1 new but got the SL0 on eBay where they come up regularly for thirty quid or so.
Click to expand...

Your post has jogged my memory and the torque wrench I have had for over thirty years is a Norbar. I wonder if they ever go out of calibration? I try to remember to slacken off the torque adjustment when I put it away as I think that's what the instructions advised...?
 
Norbar are imho the best torque products. Quite reasonable priced when compared to snap-on etc. they are made in the UK and are available from the likes of Cromwell tools.
 
john_morris_uk said:
I wonder if they ever go out of calibration?
Click to expand...

Yes, they can go out of calibration. Like any decent tool, they need an element of care and maintenance. We use a lot of torque wrenches at work as we're manufacturers of mechanical transmissions. One product, a driving hub for a tracked, military vehicle, has a nut fastened to 400 Nm. 3 Weetabix in a morning is required to pull that one down. All of our wrenches must be calibrated regularly, same as thread gauges, plug gauges, slip gauges and so on. Yes, it's good practice to put them away with the setting slackened off. A full calibration should be done and certified in Lab conditions but it's not hard to check a few settings. As has already been noted, torque is merely load over a distance. Time to find those old 56 lb weights!
 
Last edited:
JumbleDuck said:
The worst thing I have ever had to undo/redu was the front hub nut on a 2CV, which from memory is 240Nm. 3/4" drive socket, breaker bar, six feet of scaffold pipe, jump.
Click to expand...

That brings back a memory of a siezed wheel nut on an old merc. I had a half-decent 1/2" socket set and a 10ft steel tube that was starting to flex worryingly when there was a bang and a whizzing sound as half a socket went past my ear to riccochet around the garage. I never did find the other half that went out into the yard. It took the garage 5 minutes solid thumping with a pneumatic air wrench to get the damn thing off
 
Stemar said:
That brings back a memory of a siezed wheel nut on an old merc. I had a half-decent 1/2" socket set and a 10ft steel tube that was starting to flex worryingly when there was a bang and a whizzing sound as half a socket went past my ear to riccochet around the garage. I never did find the other half that went out into the yard. It took the garage 5 minutes solid thumping with a pneumatic air wrench to get the damn thing off
Click to expand...

I managed to shear four of the five wheel studs on my Hunter's trailer (Landrover wheels) before discovering, on teh fifth one, that one side used left hand threads. Clearly I am not only a gorilla, but a slow learning gorilla.
 
Stemar said:
That brings back a memory of a siezed wheel nut on an old merc. I had a half-decent 1/2" socket set and a 10ft steel tube that was starting to flex worryingly when there was a bang and a whizzing sound as half a socket went past my ear to riccochet around the garage. I never did find the other half that went out into the yard. It took the garage 5 minutes solid thumping with a pneumatic air wrench to get the damn thing off
Click to expand...
That's what 3/4" socket sets are for ;)
We used to service some delivery wagons and always had a trouble with the crankshaft pulley nut. It's the falling on your arse when the big bar gives that is the worst bit.
 
JumbleDuck said:
The worst thing I have ever had to undo/redu was the front hub nut on a 2CV, which from memory is 240Nm. 3/4" drive socket, breaker bar, six feet of scaffold pipe, jump.
Click to expand...

I replaced both front wheel bearings on a 2CV. They are retained by a screwed ring about 3 inches in diameter with slots on opposing sides to take a tool. I cut a bit of 1/2 inch bar to fit, held it in stilsons with a bar slipped over the handle. The piece of bar bent immediately. Next day I cut the same size tool from a piece of En24 at work, hardened and tempered it and tried again. The tool was excellent, didn't deform at all, but an 8 ft bar over the stilsons, which was the length we needed to turn the ring, bent the stilsons, which are the same to this day.
 
boguing said:
After a bit of asking around various types of aircraft engineers I bought one of the Halfords Pro range, which was then tested and found to be exactly what it's certificate said. Their 3/8" had a better than average upper range too.
Click to expand...

Halfords pro stuff is generally very good indeed. I once broke the jaw end of a 6mm combination spanner (wasn't quite up to undoing the safety clamp on a Citroen DS suspension) and it was replaced instantly and with no question. In fat, I didn't have to say anything at all; as I walked up to the first chap I saw, spanner in hand, he took it from me, waved it over his head and called "Another one of these, 6mm" to his colleague by the tool stand. I was on my way again in under a minute. No nonsense about receipts or anything either - lifetime guarantee and all that.

Their flexi-head ratchet combination spanners are superb, by the way. Most useful things I have ever bought.
 
You must log in or register to reply here.

Share this page

Top