[Bad Rat 414]

Cool!

[oldred]

Hippie, How do you intend to test the torque on the bolt? That is, from what is being said here the extension would affect torque applied to the bolt(it will not) but not the reading from the wrench itself. What I asked earlier about using two torque wrenches connected with an extension would be the only way to do this without using calibration equipment. The only meaningful way to do this would be to measure the wrench reading against a known torque value and there is no reliable way to do this using a fastener. It seems fairly simple but I can't get this guy to answer my question, If you connect two torque wrenches together with an extension will one read less than the other? Which one? Why? If you have two people simply holding the wrenches unsupported and trying to apply torque you would induce variables since it would be nearly impossible for both to apply force at exactly the same angles which theoretically would not matter but mechanically induced error would probably occur. If you attempt to support the extension, say inside a pipe locked in a vise, then there still would likely be a problem with friction between the pipe and extension which could cause erroneous readings. Torquing a bolt with or without an extension and then trying again with or without the extension proves nothing either since almost every time you torque a fastener to it's proper value and then let it "rest" a while it will move slightly most times if re-torqued. All these variables are what causes this misunderstanding in the first place and all too often one of these flawed "tests" are used to come to the wrong conclusion. Simple laws of physics apply here and are quite clear(obviously to the manufacturers also since no "correction" data is included). This guy cannot be convinced no matter what you do because he already knows the truth and is simply obsessed with proving he is right no matter what it has done to his creditability so far.

[oldred]

Hippie, My apologies, I read your post quickly and did not realize the kind of equipment you have on hand.

[Bad Rat 414]

Oldred, now you've thrown me off. I'm not sure what your talking about connecting two torque wrenches. I did find a site with this talked about. I'm talking about using an exstention on the drive not the handle. Just to make it plain I am talking about an extension not an adapter. Here's that site: http://www.specialpatrolgroup.co.uk/...ue/torque.html

[Bad Rat 414]

I'm really not sure what that site is talking about at the bottom of the page.

[oldred]

Rat, Ok for the record I am talking about a common socket extension that extends 90 deg from the wrench handle. I did not realize what hippie had to do this test with at first so maybe he can do it but any error would have to be mechanically induced. I am talking about theory using two torque wrenches connected by an extension,(one could be thought of as the fastener) one at the connector end and the other at the socket end, now apply a given torque setting to either one and would one read less than the other? which one? why? I think the answer to this is quite obvious and for someone to argue that things like inertia from the mass of an extension affecting a properly used torque wrench is just plain ridiculous. I wonder if he even realizes that inertia would only be a factor during acceleration or deceleration and would have no effect on a steady pull or even if he really knows what inertia is.

[oldred]

Rat, I went back to the bottom that page and I think you might be talking about being sure the wrench is in line with the extension? If it were allowed to swing to an angle this would effectively shorten the extension(adapter) and give an erroneous reading.

[Hippie]

One thing you have to remember is that torque wrenches are considered to be "in calibration" if they can repeat a torque setting within 10% on 3 seperate pulls. Usually they will repeat much closer than that but I honestly doubt there will be more than a 10% variation between the test with and without the extension. In other words I doubt you'll see enough difference to make any definite conclusion but if the variation falls within 10% I think we can say that effectively there is not enough difference to have a detrimental affect on the final torque at the fastener. We shall see.........

[oldred]

Hippie, The laws of physics(along with the wrench manufacturers) plainly state it can have no effect. This has been accepted since torque wrenches have been in existence and used accordingly on everything from lug nuts to the space shuttle. It is amazing how this old myth refuses to die but as I pointed out earlier it has caused many equipment and engine failures due to over-torqued fasteners and I am sure that it will continue to do this. If someone only adds a couple of pounds to a 75 ft/lb setting for instance then not much will happen but when they attempt to add 10% or so it can result in disaster.

[Hippie]

Originally Posted by oldred

If someone only adds a couple of pounds to a 75 ft/lb setting for instance then not much will happen but when they attempt to add 10% or so it can result in disaster.

And yet how many of us bother to have our torque wrenches checked occasionally? You would be amazed at the variation that can occur over 6 months or a year depending on how much the wrench is used or abused or if it is improperly stored. I usually only see a Ft Lb or 2 on most wrenches but I have seen some lose or gain as much as 15% accuracy. Of course we have people that think they are breaker bars, pry bars and ball peen hammers. Nobody but NOBODY gets to borrow my torque wrench!

As far as the physics of it is concerned I'm not arguing with anybody, I'm just going to do a test. If there IS any torque lost through an extension I seriously doubt it would be measurable but since I have the equipment available and I'm doing the checks anyway what the heck?! You guys have been arguing this for how long now? Wouldn't it be nice to have a test done on some accurate test equipment? My gut instinct tells me "physics" will be vindicated. I've been doing this for nearly 20 years, I'm getting fairly good at it so sit back relax and wait for the results.

[NXS]

Mythbusters...here we come!

For the record I said we had a 4% variance in our little shop tests, not 10%.

This guy cannot be convinced no matter what you do because he already knows the truth and is simply obsessed with proving he is right

I am not "This guy", I am Nisan Catron. I am not obsessed...but you may be. but I am anxious to see Hippies tests. I've also attatched some pics to help show what I've been saying:

[oldred]

What YOU have been saying , Thats what we have been telling YOU all along. How many times have we told you that TILTING the extension will affect the applied torque by introducing a leverage factor into the equation. There are many ways to improperly use a torque wrench or any other tool and that holding illustration is just another example of a mechanically induced error. What they are saying is DON'T DO THAT that shows how NOT to use a torque wrench! What exactly do you think you have found here? This started when you tried to say that an extension would be in error because of twisting and you could not prove that so you have gone off in several other directions since claiming everything from inertia to a full moon would effect the reading.

How much time have you spent searching the net for info to back up your point and you say you are not obsessed? If you would have the common courtesy to answer just ONE question I would like for you to explain why it is so hard to find credible info to back up what you STARTED OUT saying but the opposite info is easy to find, why is that? If you can't answer that then how about which one of those torque wrenches connected together would read less, which one? Why?

[Bad Rat 414]

LOL, don't forget he also said it makes a difference where you put your hands on the torque wrench.

[oldred]

Rat, He's come full circle now he is trying to say exactly what we have told him from the start. He comes up with something showing how using a wrench improperly will give an erroneous reading and then says "see here this proves what I have been saying"

[NXS]

It DOES matter where you put your hand on the Tq wrench.
I haven't changed what I've said since the beginning.
Obsessed? You've had 10 posts of the last 23 and I've had 3. I'm done.
-ciao