That is to torque left hand threads. She is right. If you care about your torque wrench you shouldn't do it.Aguacate said:
That is to torque left hand threads. She is right. If you care about your torque wrench you shouldn't do it.Aguacate said:Do you use a torque wrench to remove bolts? The lady at NAPA said never to do so, but why would they give you the option of changing the ratchet direction if you shouldn't go backwards.
When a fastener is first loosened it often takes a much larger amount of "reverse" torque to break it loose. That is what will damage the wrench.howley said:I understand that, but how is using a the tool to loosen a bolt any different from using it to tighten a higher torque left hand thread?
I completely agree with you, and not to argue or anything but just to understand, let's say you set the torque wrench to 100 ft-lbs. Now you go to remove a bolt. Let's say that the torque wrench removes the bolt without clicking. This means that you used less than 100 ft-lbs of torque, right? Now let's say you are at the last bit of a left-handed bolt requiring 100 ft-lbs of torque and you use the torque wrench until it clicks. In this case you've applied more torque to do what it's meant to than to loosen a bolt.ducpainter said:When a fastener is first loosened it often takes a much larger amount of "reverse" torque to break it loose...
It click so it doesn't over-torque. If you continued past that point you would damage the wrench the same wayAguacate said:I completely agree with you, and not to argue or anything but just to understand, let's say you set the torque wrench to 100 ft-lbs. Now you go to remove a bolt. Let's say that the torque wrench removes the bolt without clicking. This means that you used less than 100 ft-lbs of torque, right? Now let's say you are at the last bit of a left-handed bolt requiring 100 ft-lbs of torque and you use the torque wrench until it clicks. In this case you've applied more torque to do what it's meant to than to loosen a bolt.
Either way I think it just makes sense to use a torque wrench as MTL-DUC has described.
But if you have the wrench set to a high torque value, how is it any different to doing a left hand thread up really tight, providing you don't go past the click? I'm not saying anyone is wrong, but I need a explanation for why I can't do it.ducpainter said:When a fastener is first loosened it often takes a much larger amount of "reverse" torque to break it loose. That is what will damage the wrench.
Ducpainter gave the explanation. Usually the break away torque is greater than the installation torque. You will particularly notice this on your oil screen. Add to this the electrolytic action between the fastener material and the part material and you have a problem. We won't even mention the gorilla who worked on your bike last.howley said:But if you have the wrench set to a high torque value, how is it any different to doing a left hand thread up really tight, providing you don't go past the click? I'm not saying anyone is wrong, but I need a explanation for why I can't do it.
You won't damage the wrench if the wrench is set higher than the torque required to break the fastener loose. You cannot measure or calculate the breakaway torque. It's not worth the chance of ruining an expensive wrench.howley said:Yeah i see that the break away torque is much higher. But if you were to torque a left hand threaded nut up to the other nut's breakaway torque, would it then damage the wrench?
Yes.howley said:So provided you don't torque past the click trying to undo the bolt it won't damage the wrench?
$200? You bought a cheap one. I have the Techwrenches from Snap-On ( I used to make a living with them) The 1/2" and 3/8" IIRC they were about 600 or so each. Not saying you have to spend that much, just get a quality one from the start, and be careful not to drop it. I had someone drop my in/lb one. Cost $100 bucks to recalibrate itpnut said:Just use your $200 torque wrench any way you want. Let us know how it turns out.