Originally Posted by Triloc
I was actually thinking about the TW-2 for tightening the crankarms.
They need to be tightened to 12-15NM and the TW-2 spans from 0-67.8Nm (0-600 lb-in).
Would that do the trick?
The following assumes you want to torque correctly ...
If you take into consideration the usable range of the wrench and the accuracy of the wrench ... you may not be able to use that wrench to perform that torque.
First, this is a beam type torque wrench. Second, Park website never states accuracy of the tool so let's just assume +/- 2% of Indicated Value for. I could be better, could be worse, we don't know yet.
The industry standard for usable ranges of a torque wrench is 20% of full scale to 100% of full scale.
So if the top is 67.80Nm, 20% would be 13.56. So 13.56Nm would be the lowest acceptable reading with that torque wrench. The picture of the torque wrench at the Park site shows 5Nm increments. So to do your 12-15Nm torque, the pointer would need to land right on 15Nm.
And we haven't considered accuracy yet. Assuming a +/- 2% accuracy at 15Nm, this is a +/- .3Nm uncertainty. So a reading of 15Nm, could be anywhere between 14.7 and 15.3. Since 15.3 is outside the range of your torque (12-15) you would need to subtract that from the end of your torque, ie adjusted setting of 14.7. But wait, you can't torque to 14.7. The increments are 14nm or 15nm. Good torque practice with a dial or pointer indicator is to land on a "tick" mark ... not between "ticks"
So basically, in order to torque to this spec properly, you need a different torque wrench.
Yep ... those 0 to whatever torque wrenches sure look inviting but without knowing the usable range of the wrench or it's accuracy ... you might as well use your open end wrenches to perform the torque.
If you are going to measure your torque, measure accurately ... otherwise why bother.