Torque Amp

[Insaneride]

Based on these links (and my own formulas) you would only have 420 ft/lbs.

Wrench setting = 100
Original length = 1.25 ft (from the center of the grip)
Overall length = 1.25' + 4' = 5.25 ft

http://www.norbar.com/calculators/to...alculator.aspx
http://www.norbar.com/Calculators/To...alculator.aspx

Your wrench needs to be set approx 132 ft/lbs to get the desired 556 ft/lbs.

Dave J.

I will try to keep this math coherent.

Reading between the lines of MACs method. His error multiplied times point 0.8 seems to be dead nuts on.

5.25 feet X torque at wrench X 0.8 equals actual torque

No?

[leightrepairs]

To keep the math easier there is an app for that. I mostly use one on Android called Torque wrench calculator. You simply put in the different measurements and this one lets you pick from one of 4 angles 0,45, 90, or 135 and it tells you what to set the wrench to.

[Insaneride]

speeddr2000 shared this link http://www.engineersedge.com/manufac...e_wrench_1.htm

This calculator link still works. You got to navigate tho

Thanks

speeddr2000

[MinnesotaDave]

I will try to keep this math coherent.

Reading between the lines of MACs method. His error multiplied times point 0.8 seems to be dead nuts on.

5.25 feet X torque at wrench X 0.8 equals actual torque

No?

To be honest, I don't know why you guys are trying to change how you view such a simple formula.
But every variation of the formula is directly related to it since the physics don't change - so have at it

[William McCormick]

To be honest, I don't know why you guys are trying to change how you view such a simple formula.
But every variation of the formula is directly related to it since the physics don't change - so have at it

Because there are other forces at work. As I mentioned I use a crow's foot with a 3/8" square drive 12" extension between the crow's foot and the ratchet wrench to reach up into the ceiling, I turn the ratchet wrench to reach up into a ceiling to install and adjust mini-split cassettes. Used like that it works with the ratchet wrench in any position not just parallel and in line with the crow's foot. So in that scenario, you have to calculate the length of the wrench you use as the multiplication factor of torque. But if that is the case, when it is in line like in the original poster's situation and on the same plan no 3/8 square drive extension, you should get the torsional power applied to the crow's foot as well as the power of the lever applied to the crow's foot, giving you more torque on the bolt you are tightening than the formula claims. When you use two devices instead of just one large torque wrench you should get very different results for the same force applied by your hand. What I was saying is that a quick look at the formula and you think maybe that it is taking into consideration all that. But upon closer examination, the formula just takes the pressure of your hand on the wrench and multiplies it by the length of the torque wrench. That is not compensating for the rotational torque applied by the torque wrench to the extension lever that is also a lever. The formula is just treating the two devices like one long lever and then calculating how much the torque wrench will read which should give the wrong result. I will bet someone somewhere had broken some bolts using that formula.

Sincerely,

William McCormick

[William McCormick]

To be honest, I don't know why you guys are trying to change how you view such a simple formula.
But every variation of the formula is directly related to it since the physics don't change - so have at it

If it was a single lever the formula would be for the original poster's situation, Torque needed 556 ft. lbs. divided by the distance of the center of your hand from the center of the bolt 5.25 feet so 556 ft. lbs. divided by 5.25 feet gives you 105.904 pounds needed, which tells you what your hand should apply to the end of the single-lever 105.904 pounds. Then the formula goes on and claims that if your hand is applying 105.904 pounds then the wrench reads 132.380 because you just multiply 105.904 times the length of the wrench which was 1.25 and you get 132.280 but that is like no shat-sherlock. I am saying that it just cannot match the reality.


I am saying that once you add a fulcrum point for lack of a better term, in the middle of a single lever you are going to get different effects than that of a single lever.

Sincerely,

William McCormick

[William McCormick]

To keep the math easier there is an app for that. I mostly use one on Android called Torque wrench calculator. You simply put in the different measurements and this one lets you pick from one of 4 angles 0,45, 90, or 135 and it tells you what to set the wrench to.

That app claims you need 173 ft. lb torque wrench settings for the original posters scenario fascinating. I am trying to get two similar torque wrenches to do some testing.

Sincerely,

William McCormick

[William McCormick]

I just ordered two identicle torque wrenches, I am going to get to the bottom of this if only for my own sanity.


Sincerely,

William McCormick

[Insaneride]

Because there are other forces at work. As I mentioned I use a crow's foot with a 3/8" square drive 12" extension between the crow's foot and the ratchet wrench to reach up into the ceiling, I turn the ratchet wrench to reach up into a ceiling to install and adjust mini-split cassettes. Used like that it works with the ratchet wrench in any position not just parallel and in line with the crow's foot. So in that scenario, you have to calculate the length of the wrench you use as the multiplication factor of torque. But if that is the case, when it is in line like in the original poster's situation and on the same plan no 3/8 square drive extension, you should get the torsional power applied to the crow's foot as well as the power of the lever applied to the crow's foot, giving you more torque on the bolt you are tightening than the formula claims. When you use two devices instead of just one large torque wrench you should get very different results for the same force applied by your hand. What I was saying is that a quick look at the formula and you think maybe that it is taking into consideration all that. But upon closer examination, the formula just takes the pressure of your hand on the wrench and multiplies it by the length of the torque wrench. That is not compensating for the rotational torque applied by the torque wrench to the extension lever that is also a lever. The formula is just treating the two devices like one long lever and then calculating how much the torque wrench will read which should give the wrong result. I will bet someone somewhere had broken some bolts using that formula.

Sincerely,

William McCormick

That's funny, "I bet someone somewhere broke bolts with that formula".

Minnesota Dave, I try not to be so narrow minded and simplicity is sometimes a sign of genius. Trying to impress with simple formulas isn't that impressive. Btw, your links for torque calculator don't work anymore but speeddr2000 's link still work. So does MACs simple method of multiplying total tool length times torque displayed times 0.8.

I used to do Trig in my head up to 3 degrees but I don't try to pretend to be mathematician.

[William McCormick]

That's funny, "I bet someone somewhere broke bolts with that formula".

Minnesota Dave, I try not to be so narrow minded and simplicity is sometimes a sign of genius. Trying to impress with simple formulas isn't that impressive. Btw, your links for torque calculator don't work anymore but speeddr2000 's link still work. So does MACs simple method of multiplying total tool length times torque displayed times 0.8.

I used to do Trig in my head up to 3 degrees but I don't try to pretend to be mathematician.

I don't think this is math as much as it is the application of math. Considering all the variables, which is actually science and physics basically, the scientific method as it used to be taught. The old scientific method made you demonstrate the hypothesis you wished to prove with the experiment you wished to do to prove it, and then you would list all the variables in the experiment that might give you wrong results and if you could not remove the variables you would do the experiment and list the variables with the experiment. Math would come after all of this. I am pretty sure that is not what is happening today. Just before 1973, they changed the scientific method in all books to exclude demonstrating your hypothesis, because after World War Two they openly announced that they were going to hide the atom and atom bomb from citizens of earth. At that time they introduced the phony force of attraction or as they called it cohesion that does not exist in our universe. All apparent attraction forces are pushing forces if you dissect them. They then claimed the neutron existed by forces of cohesion which of course, they could not demonstrate a force of cohesion in our universe. So they changed the scientific method and now just say "see dirt is pulled into the vacuum, proof." Yet, of course, hands-on folk knew that the vacuum pump in any vacuum pressurizes air in the pump and expells it from the vacuum. This creates less pressure in the vacuum chamber and dirt, is blown into that vacuum with the pressure of the atmosphere around the vacuum. Magnets, gravity it is all the same if you dissect it.

Sincerely,

William McCormick

[leightrepairs]

That app claims you need 173 ft. lb torque wrench settings for the original posters scenario fascinating. I am trying to get two similar torque wrenches to do some testing.

Sincerely,

William McCormick

So I plugged the figures from the original post into the app, wrench length 1.25 ft = 15 inches, 4 ft = 48 inches and a desired torque of 556 lbs and it says to set torque wrench to 132 ft-lbs. This number is the same as what Dave posted in his first response.

[William McCormick]

So I plugged the figures from the original post into the app, wrench length 1.25 ft = 15 inches, 4 ft = 48 inches and a desired torque of 556 lbs and it says to set torque wrench to 132 ft-lbs. This number is the same as what Dave posted in his first response.

I tried it again and got the same result. But again all that is doing is taking the overall length and dividing it into the torque wanted on the bolt which gives you the force your hand has to put on the wrench. From there it just multiplies the force of your hand by the length of the torque wrench. So it is not calculating anything about the two different objects. Rather it is just giving you the torque reading your hand will create upon the torque wrench. We know you could get a hanging scale and attach it to the torque wrench and pull till you hit 105 lbs. on the scale, and that will create 556-foot pounds of torque 5.25 feet away if you are using a single breaker bar. But all that formula does is give you the theoretical force delivered to the bolt through two different levers. At four feet where the torque wrench attaches to the extension, you need 139 pounds on the lever, 556 divided by 4 equals 139. So what could that formula be doing? Other than just taking the force of your hand and multiplying it by the length of the torque wrench, which has to be wrong.

I think I input the numbers incorrectly on that calculator earlier, but that is all the more reason to understand what the calculator is or is not doing for you.



Sincerely,

William McCormick

[William McCormick]

So I plugged the figures from the original post into the app, wrench length 1.25 ft = 15 inches, 4 ft = 48 inches and a desired torque of 556 lbs and it says to set torque wrench to 132 ft-lbs. This number is the same as what Dave posted in his first response.

You can also plugin 1.25 and 5.25 and it will also give you 132-foot pounds of torque. But again I cannot see how that can be accurate, considering that you can turn a crow's foot even if you use a 12-inch long socket extension between the crow's foot and your wrench. You lose the inline lever force in that scenario which should make the formula in question, questionable.

The formula just uses the ratio between those two numbers.

Sincerely,

William McCormick

[leightrepairs]

Yes you can turn the crows foot, which is why there is a provision on the app to calculate it at different angles. Yes this is limited to only a couple of choices so not perfect. Yes using an extension between the torque wrench and crows feet introduces a whole new set of variables. You would have losses due to the twisting of the extension and the side forces caused by the torque wrench and crows foot being in a different planes from each other. However none of these forces are a factor in the OP. There is also usually a range specified when torque's are specified. When you get right down to it a torque wrench is not the most accurate way to tighten a fastener as there are a lot of variables that are hard to take into consideration. Torque and angle measurement is more accurate. https://www.norbar.com/News-Events/B...ngle-Explained Then you could always do it by measuring the stretch of the bolt, this gives a much more reliable way to determine the clamp force of the fastener.

[12V71]

Yes you can turn the crows foot, which is why there is a provision on the app to calculate it at different angles. Yes this is limited to only a couple of choices so not perfect. Yes using an extension between the torque wrench and crows feet introduces a whole new set of variables. You would have losses due to the twisting of the extension and the side forces caused by the torque wrench and crows foot being in a different planes from each other. However none of these forces are a factor in the OP. There is also usually a range specified when torque's are specified. When you get right down to it a torque wrench is not the most accurate way to tighten a fastener as there are a lot of variables that are hard to take into consideration. Torque and angle measurement is more accurate. https://www.norbar.com/News-Events/B...ngle-Explained Then you could always do it by measuring the stretch of the bolt, this gives a much more reliable way to determine the clamp force of the fastener.

No such thing as torque loss through twist on an extension unless it begins to permanently deform. Torque in is torque out if it is steadily applied, you might see flex but you aren't losing torque. That theory has been debunked many times over.
The Shane Conley videos on you tube are pretty good at explaining all this stuff.

[leightrepairs]

12V, I watched the Shane Conley video on the extensions, to me that was not very convincing. I have nothing to back up what I was taught with regard's to extension causing a loss. This is just what I was taught years ago and always have thought to be true and avoid using extensions when torqueing fasteners. With that said I am betting you will agree that with an extension on an impact wrench you lose power to break bolts loose, which seems to back up what the old German taught me.

[12V71]

12V, I watched the Shane Conley video on the extensions, to me that was not very convincing. I have nothing to back up what I was taught with regard's to extension causing a loss. This is just what I was taught years ago and always have thought to be true and avoid using extensions when torqueing fasteners. With that said I am betting you will agree that with an extension on an impact wrench you lose power to break bolts loose, which seems to back up what the old German taught me.

Yes, but that is harmonics from the impact. the same reason "torque sticks" can control input torque with an impact wrench. Otherwise they are just another extension.
Steady pull has nothing to do with impact losses.

[William McCormick]

No such thing as torque loss through twist on an extension unless it begins to permanently deform. Torque in is torque out if it is steadily applied, you might see flex but you aren't losing torque. That theory has been debunked many times over.
The Shane Conley videos on you tube are pretty good at explaining all this stuff.

You are correct. You will however have to move the end of the wrench more while it is under a load it will take longer and it may feel like you are applying more force. What you will be applying is more energy to achieve the same result, same pressure just more energy.


Sincerely,

William McCormick

[12V71]

You are correct. You will however have to move the end of the wrench more while it is under a load it will take longer and it may feel like you are applying more force. What you will be applying is more energy to achieve the same result, same pressure just more energy.


Sincerely,

William McCormick

It's just wind up. That's where the old wives tales about extension losses started.

[William McCormick]

No such thing as torque loss through twist on an extension unless it begins to permanently deform. Torque in is torque out if it is steadily applied, you might see flex but you aren't losing torque. That theory has been debunked many times over.
The Shane Conley videos on you tube are pretty good at explaining all this stuff.

What the socket extension causes between the torque wrench and the crow's foot, is the loss of lever force. We know that when you use a crow's foot and socket extension between the torque wrench that you no longer have different forces applied to the crows from the torque wrench at different angles. Now the crow's foot turns by torque alone no added force from the torque wrench acting like a lever extension anymore. Now it is just multiplication of the lengths of the two devices to get total torque applied. But if the two devices are inline and you were to change the angle of the torque wrench in 90-degree intervals, at different angles you will get either the addition of the force added by the length of the torque wrench or subtraction of force based on the angle of the torque wrench, as well as the known torque as indicated by the torque wrench. That is why if you do not use a socket extension you would get different amounts of torque applied to the bolt as the torque wrench was at different angles even if you maintained the same torque reading on the wrench.

Sincerely,

William McCormick

[William McCormick]

12V, I watched the Shane Conley video on the extensions, to me that was not very convincing. I have nothing to back up what I was taught with regard's to extension causing a loss. This is just what I was taught years ago and always have thought to be true and avoid using extensions when torqueing fasteners. With that said I am betting you will agree that with an extension on an impact wrench you lose power to break bolts loose, which seems to back up what the old German taught me.

You lose power, not Torque. The impact wrench may not be able to deliver the same foot-pounds through a socket extension but that is timing, the twisting of the socket extension takes time, the impact wrench might reach full force before the socket extensin can deliver full force, as soon as the impact intermittently stops applying force, instantly force is no longer applied to the bolt being tightened so it seems to eat up the power of the impact wrench and it does, and it will certainly eat up shock hammer-force. There could be a dead-blow type of effect caused by a socket extension that might shear off a smaller bolt with almost unbelievable efficiency though, but all of that is the art of sizing and timing. A constant torque device will deliver constant torque through a socket extension.


Sincerely,

William McCormick

[Insaneride]

I just ordered two identicle torque wrenches, I am going to get to the bottom of this if only for my own sanity.


Sincerely,

William McCormick

That's just crazy.

What if one or both are out of calibration by say 10%. And also, one of them is out 10% negative and the other is out 10% positive then you will have a 20% error. Another great MAC, one could be broken or defective outa the box. Crude methods and acceptable methods of calibration have been shown. Please just keep it crazy. Your rhetoric can be difficult to read between the lines after lines.

MAC, your simple method is easiest to use and hardest to forget

LENGTH in feet (4' + 1.25 = 5.25) multiplied times the value displayed on tool result times 0.8 is faster easier than grabbing a scientific calculator
No?

[12V71]

What the socket extension causes between the torque wrench and the crow's foot, is the loss of lever force. We know that when you use a crow's foot and socket extension between the torque wrench that you no longer have different forces applied to the crows from the torque wrench at different angles. Now the crow's foot turns by torque alone no added force from the torque wrench acting like a lever extension anymore. Now it is just multiplication of the lengths of the two devices to get total torque applied. But if the two devices are inline and you were to change the angle of the torque wrench in 90-degree intervals, at different angles you will get either the addition of the force added by the length of the torque wrench or subtraction of force based on the angle of the torque wrench, as well as the known torque as indicated by the torque wrench. That is why if you do not use a socket extension you would get different amounts of torque applied to the bolt as the torque wrench was at different angles even if you maintained the same torque reading on the wrench.

Sincerely,

William McCormick

I see what you are saying here regarding the angle of a crowsfoot or any other torque adapter, but a socket extension (bar with male/female square drive) has no effect on applied torque, only the length and/or angle of the torque adapter center to center. I've used Dave's formula for years and most equipment manuals have that same formula in their general specifications section.

[Insaneride]

I see what you are saying here regarding the angle of a crowsfoot or any other torque adapter, but a socket extension (bar with male/female square drive) has no effect on applied torque, only the length and/or angle of the torque adapter center to center. I've used Dave's formula for years and most equipment manuals have that same formula in their general specifications section.

Really?

speeddr2000 provided original link in a Samm thread that has a working link at this time

https://www.engineersedge.com/manufa...orque_wrench_1.


The method MAC uses times 0.8 seems to be dead nuts.

I think Xsbanks used a similar method in another thread for ball park accuracy. I Could be wrong tho

MAC method times 0.8 is better imo

[William McCormick]

That's just crazy.

What if one or both are out of calibration by say 10%. And also, one of them is out 10% negative and the other is out 10% positive then you will have a 20% error. Another great MAC, one could be broken or defective outa the box. Crude methods and acceptable methods of calibration have been shown. Please just keep it crazy. Your rhetoric can be difficult to read between the lines after lines.

MAC, your simple method is easiest to use and hardest to forget

LENGTH in feet (4' + 1.25 = 5.25) multiplied times the value displayed on tool result times 0.8 is faster easier than grabbing a scientific calculator
No?

I am going to test the two wrenches against each other first. Then do some testing with different length crows feet.

Yea, I am not sure of any formula until I actually test it out. Crane Builders, building architects, automotive engineers, they don't need to check it out, I do though.

Sincerely,

William McCormick