Rear axel bolts keep breaking?
03-27-2012, 03:34 AM
#31
Three Wheelin'
The accuracy of tightening a threaded fastener with an open end wrench or ratchet is only about +/- 20% to 50%.
Your typical click release torque wrench will get you in the +/- 10% to 20%.
The more sophisticated stuff is about +/- 5%
That puts the best assembly workers (or mechanics) on par with your worst torque verification tool.
You might be looking at these numbers and thinking "hey, my torque wrench says its accurate to +/- 2%, why are you saying 10% to 20%!?"
Really, these are two different measures. The tool accuracy is +/- 2% of torque application. Torque application is just an indicator of fastener tension (the true goal is tension). When you add the real word variations of a threaded joint, the accuracy of a certain torque, equaling a certain tension, diminishes. Thats why a $10,000 tool (I'm not joking) will only get you within 5%.
Sorry to digress, but it was a little bit on topic, and it doesn't hurt to know a little more about why you should purchase and use a decent torque wrench.
Saga- You can put a lever arm extension on the end of your, larger, torque wrench to get up to 368 lb-ft. Provided you keep the extension lined up with the tool handle, the change in torque setting equation is really simple.
Your typical click release torque wrench will get you in the +/- 10% to 20%.
The more sophisticated stuff is about +/- 5%
That puts the best assembly workers (or mechanics) on par with your worst torque verification tool.
You might be looking at these numbers and thinking "hey, my torque wrench says its accurate to +/- 2%, why are you saying 10% to 20%!?"
Really, these are two different measures. The tool accuracy is +/- 2% of torque application. Torque application is just an indicator of fastener tension (the true goal is tension). When you add the real word variations of a threaded joint, the accuracy of a certain torque, equaling a certain tension, diminishes. Thats why a $10,000 tool (I'm not joking) will only get you within 5%.
Sorry to digress, but it was a little bit on topic, and it doesn't hurt to know a little more about why you should purchase and use a decent torque wrench.
Saga- You can put a lever arm extension on the end of your, larger, torque wrench to get up to 368 lb-ft. Provided you keep the extension lined up with the tool handle, the change in torque setting equation is really simple.
03-27-2012, 10:34 AM
#32
Addict
Rennlist Member
Rennlist Member
These post are exactly why I love Rennlist. Here is a young man making a few mistakes and instead of belittling him we have taught him and a few of us something. Great work Rennlist!!
03-27-2012, 11:39 AM
#33
Rennlist Junkie Forever
The accuracy of tightening a threaded fastener with an open end wrench or ratchet is only about +/- 20% to 50%.
Your typical click release torque wrench will get you in the +/- 10% to 20%.
The more sophisticated stuff is about +/- 5%
That puts the best assembly workers (or mechanics) on par with your worst torque verification tool.
You might be looking at these numbers and thinking "hey, my torque wrench says its accurate to +/- 2%, why are you saying 10% to 20%!?"
Really, these are two different measures. The tool accuracy is +/- 2% of torque application. Torque application is just an indicator of fastener tension (the true goal is tension). When you add the real word variations of a threaded joint, the accuracy of a certain torque, equaling a certain tension, diminishes. Thats why a $10,000 tool (I'm not joking) will only get you within 5%.
Sorry to digress, but it was a little bit on topic, and it doesn't hurt to know a little more about why you should purchase and use a decent torque wrench.
Saga- You can put a lever arm extension on the end of your, larger, torque wrench to get up to 368 lb-ft. Provided you keep the extension lined up with the tool handle, the change in torque setting equation is really simple.
Your typical click release torque wrench will get you in the +/- 10% to 20%.
The more sophisticated stuff is about +/- 5%
That puts the best assembly workers (or mechanics) on par with your worst torque verification tool.
You might be looking at these numbers and thinking "hey, my torque wrench says its accurate to +/- 2%, why are you saying 10% to 20%!?"
Really, these are two different measures. The tool accuracy is +/- 2% of torque application. Torque application is just an indicator of fastener tension (the true goal is tension). When you add the real word variations of a threaded joint, the accuracy of a certain torque, equaling a certain tension, diminishes. Thats why a $10,000 tool (I'm not joking) will only get you within 5%.
Sorry to digress, but it was a little bit on topic, and it doesn't hurt to know a little more about why you should purchase and use a decent torque wrench.
Saga- You can put a lever arm extension on the end of your, larger, torque wrench to get up to 368 lb-ft. Provided you keep the extension lined up with the tool handle, the change in torque setting equation is really simple.
TonyG
03-27-2012, 01:53 PM
#34
Racer
Could you explain a little more about how to do this?
03-27-2012, 03:50 PM
#35
Three Wheelin'
Sure, but I'll be lazy and just post a link I found on the subject. It has all the same equation info that I would have type out, plus a torque calculator and diagrams.
http://www.freeinfostuff.com/TorqueE...eExtension.htm
Just remember to keep the tools' center lines, lined up. If the extension goes off at an angle, you'll have to calculate the distance from the handle center to the socket center. This can be done with a little geometry, but its easier to just keep the parts lined up.
http://www.freeinfostuff.com/TorqueE...eExtension.htm
Just remember to keep the tools' center lines, lined up. If the extension goes off at an angle, you'll have to calculate the distance from the handle center to the socket center. This can be done with a little geometry, but its easier to just keep the parts lined up.
