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I have seen several posts in the last few weeks where guys need to tighten something to a specific torque, but don't have a torque wrench.
Torque wrenches are expensive, and typically one would need a few if one was a professional mechanic. The good torque wrenches are only rated for a certain range, so for the lower torques you'd need a small one, and for bigger torques you'd need a big one.
Torque wrenches also need to be calibrated from time to time, as they can become inaccurate. In the aircraft industry (where torques need to be very accurate, for obvious reasons) they are calibrated up to every 6 months. Some shops even have a "tester" where the specific torque is dialled into the torque wrench, and then the wrench is used on the tester, and checked to see if the wrench is still accurate (or that the user has in fact dialled the wrench in correctly).
What is torque?
Well, torque is usually measured in Newton-Meters. But what does this mean? Well, 10 Newtons is roughly equal to 1 kilogram. And a meter is 100 centimetres ;D
So... in order to obtain a torque of say 50NM, you can picture the following:
Have a spanner (or a socket and a long power-bar/ratchet) of 100 centimeters long. Put the spanner on the nut to be tightened, and then add a weight of 55 newtons (or 5,5kg) at the end of the spanner. When the weight stops turning the nut, you have achieved a torque of 55nm. Roughly. Remember that the weight of the spanner should be taken into account, as well as the fact that 10 newtons is not EXACTLY 1 kg. But it will be close enough, if you get my drift? Its much better than just taking a blind chance.
How can one practically apply this method?
Several ways.
For instance, when tightening wheel nuts that need to be quite tight, put the 1 meter spanner on the nut, stand on a bathroom scale, check your weight, and then apply force to the spanner until you have added the number of newtons you require for the correct torque.
Or you can get a pull-scale. Similar to what the fishermen use to weigh a fish. Attach the pull-scale to the end of your 1 meter spanner, and pull until the desired weight (torque) is achieved.
I know we don't all have a 1 meter spanner in all the relevant sizes, but you can use a shorter spanner, and adjust the torque applied respectively. It may be that for a half-meter long spanner you will need to apply double the weight (torque), but I'm not a maths genius, so I may be wrong in this.
Perhaps one of the wiser dogs can set up a table for us, with a formula, so we will know by how much to multiply the torque should we use say, a 20cm long spanner...
Thoughts/ideas?
Torque wrenches are expensive, and typically one would need a few if one was a professional mechanic. The good torque wrenches are only rated for a certain range, so for the lower torques you'd need a small one, and for bigger torques you'd need a big one.
Torque wrenches also need to be calibrated from time to time, as they can become inaccurate. In the aircraft industry (where torques need to be very accurate, for obvious reasons) they are calibrated up to every 6 months. Some shops even have a "tester" where the specific torque is dialled into the torque wrench, and then the wrench is used on the tester, and checked to see if the wrench is still accurate (or that the user has in fact dialled the wrench in correctly).
What is torque?
Well, torque is usually measured in Newton-Meters. But what does this mean? Well, 10 Newtons is roughly equal to 1 kilogram. And a meter is 100 centimetres ;D
So... in order to obtain a torque of say 50NM, you can picture the following:
Have a spanner (or a socket and a long power-bar/ratchet) of 100 centimeters long. Put the spanner on the nut to be tightened, and then add a weight of 55 newtons (or 5,5kg) at the end of the spanner. When the weight stops turning the nut, you have achieved a torque of 55nm. Roughly. Remember that the weight of the spanner should be taken into account, as well as the fact that 10 newtons is not EXACTLY 1 kg. But it will be close enough, if you get my drift? Its much better than just taking a blind chance.
How can one practically apply this method?
Several ways.
For instance, when tightening wheel nuts that need to be quite tight, put the 1 meter spanner on the nut, stand on a bathroom scale, check your weight, and then apply force to the spanner until you have added the number of newtons you require for the correct torque.
Or you can get a pull-scale. Similar to what the fishermen use to weigh a fish. Attach the pull-scale to the end of your 1 meter spanner, and pull until the desired weight (torque) is achieved.
I know we don't all have a 1 meter spanner in all the relevant sizes, but you can use a shorter spanner, and adjust the torque applied respectively. It may be that for a half-meter long spanner you will need to apply double the weight (torque), but I'm not a maths genius, so I may be wrong in this.
Perhaps one of the wiser dogs can set up a table for us, with a formula, so we will know by how much to multiply the torque should we use say, a 20cm long spanner...
Thoughts/ideas?
