Triumphrat

barneys · 06-13-2009, 01:54 PM

I have just bought a new torque wrench and have a question about the graduation markings on the barrel. One set is headed ft lbs Which I am Ok with. The other is headed M Kgs, which I although reversed, is Kilograms Metres. What I don't understand is above this scale it is marked (da N.m). What does that mean?

marc hanna · 06-13-2009, 02:08 PM

Neuton meters

39500 · 06-13-2009, 02:16 PM

daNM = Deca Newton Meter. It means Newton Meter x 10 and is commonly used in France. It may even be the correct SI unit for rotational torque.

http://www.norbar.co.uk/Portals/0/java/itc/index.html shows a conversion tool.

barneys · 06-13-2009, 02:22 PM

I realise that Nm is Newton Metres. What I can't understand is why the legend (da Nm) is immediately above the Kilogram Metre scale. I didn't think Nm & Kg M were the same, at least not according to the conversion chart supplied with the wrench.

cal6n · 06-13-2009, 03:18 PM

Hold on to your hats. Here comes the Physics.

The kilogram is a unit of mass. The Newton is a unit of force.

From your schooldays, you may remember:

Force = Mass x Acceleration

where the acceleration 9.81 ms^-2, which is approximately 10.

So 1 Newton = 10 kg and 1 kg = 0.1 Newton

What it boils down to is that 1 kilogram meter is roughly equivalent to a tenth of a Newton meter, which can be abbreviated to 1 deci (not Deca) Newton meter.

Brit twin had the right idea, but the wrong way round.

39500 · 06-13-2009, 03:27 PM

Quote:

Originally Posted by cal6n

Hold on to your hats. Here comes the Physics.

The kilogram is a unit of mass. The Newton is a unit of force.

From your schooldays, you may remember:

Force = Mass x Acceleration

where the acceleration 9.81 ms^-2, which is approximately 10.

So 1 Newton = 10 kg and 1 kg = 0.1 Newton

What it boils down to is that 1 kilogram meter is roughly equivalent to a tenth of a Newton meter, which can be abbreviated to 1 deci (not Deca) Newton meter.

Brit twin had the right idea, but the wrong way round.

1.0 NM = 0.1 daNM = 10 dNM (deci Newton Meter).

1 kgf.m = 0.9807 daNM = 9.8067 NM.

what I said was, in fact, correct. can you not count?

Get it right!

Forchetto · 06-13-2009, 03:30 PM

A Kilogram Force-Metre (kgf-m) is a unit in the category of Torque. It is also known as kilogram force metre, written as kg-m or m-kgf. It can be converted to the corresponding standard SI unit N-m by multiplying its value by a factor of 9.80665. So it's roughly 1 kg-m=10 Nm. (a Deca newton or 10 Newtons).

1 Nm= 0.74 Lbs/ft

Good converter here.

cal6n · 06-13-2009, 03:35 PM

Oops!

Just goes to show. One should always rough it out on paper first...

I stand corrected.

39500 · 06-13-2009, 03:43 PM

a slice of humble pie, sir?

barneys · 06-13-2009, 05:08 PM

Thanks guys, I understand it now. I didn't want to shear off any nuts

Back in the day when I used to wrench on my old bikes we didn't have all this metric stuff, now ft Lbs I understand!!