Explain My Torque Wrench To Me....

[dawnrazor]

Decided to fit some GB racing engine casing covers on my bike, primarily to cover the flacking paint thanks to some over zealous power washer courtesy of my ex-garage of choice.

Anyway I digress, the engine bolts need to be tightened to 10Nm - which gave me the perfect excuse to go out and buy a torque wrench. Managed to get a Teng Tools 1/4" 5-25 Nm jobbie on special so it didn't cost the earth, which is fine as it won't get a huge amount of use I imagine.

So I understand the twisty bit on the handle - twist up to the mark next to your desired torqueness and off you go, twisty twisty until it reaches required tightenedness and then the torque wrench will slip and won't tighten anymore.

Now what is puzzling me is I also have an "Angular Scale" built into the head, as you can see from the picture.

So what's that all about then, where should it be set at, and what difference does it make, 'cus I'm not getting it.

Thanks in advance from the mechanically challenged!

[dawnrazor]

Some bolts, many cylinder head bolts for example, are "stretch bolts" which you tighten to a set torque and then tighten by a further angular amount.

So if I'm told to tighten to 10Nm, then I sent the Angular Scale to 0° - otherwise it'll say 10Nm and 15° = is that right?

[ratt1er]

So if I'm told to tighten to 10Nm, then I sent the Angular Scale to 0° - otherwise it'll say 10Nm and 15° = is that right?

As far as I'm aware you set the torque at 10Nm and the angular scale at zero. Then when you tighten you will hear a click, the head wont slip round just a click. Then you'll be done.

I use torque wrenches all the time at work but i've not seen these ones with angles marked on the heads so anyone correct me if I'm wrong.

[Hendo]

As MM pointed out it is for cylinder heads etc. For 99% of what you will be using it for, you dont need/use the angular guage. Just set it to the required NM scale and away you go.

I have the exact same 1/4" torque wrench by the way. Also have the 3/8" and the 1/2" is next on my shopping list.

Andy

[Pants]

check the instructions. for instance, if you use a crows foot on the end you do not need to make an adjustment for the change in length if you set the crows foot to 90 degrees to the wrench (there is a slight difference, but its minimal).

I don't have a wrench with an angular adjustment on it, but I'd have thought a bolt designed to stretch would have that factored into its torque setting? I haven't seen a wrench with angles on it either...

[TriGGer]

As Mike said earlier, the Angular divisions are for when the specification for a certain bolt/joint are torque plus blah degrees.

It's a bit of a gimmick for home use tbh, especially on that size wrench.

Angle is used with torque widely in industry, mainly to error proof critical fastenings - torque and angle help eliminate buy off for cross threaded/damaged fastenings before an effective joint is made.

HTH

[zx6rrob]

So if I'm told to tighten to 10Nm, then I sent the Angular Scale to 0° - otherwise it'll say 10Nm and 15° = is that right?

If theres just a torque setting, then dont worry about the degrees, just use the wrench till it clicks and thats the desired torque. Go nice and steady with the wrench, don`t snatch at it, and make sure you stop at the click, not after.

Cyclinder head bolts are commonly toque+angle tightened. Rover K-series for example, from memory its 20Nm in the set sequence, then 180 degrees, then a further 180 degrees.