Giant torque wrench in Raleigh/Durham

GCncsuHD said:
The head of the bolt has nothing at all to do with the tension you can apply to the bolt via torque.

Thread pitch does have to do with the applied tension per applied torque, but in many cases is deemed negligible for real life purposes, the variance in torque wrenches is at times larger than that.

Fine threaded bolts do have more "holding power" due to the fine thread pitch creating more surface area (stress area) to divide the stress along the threads, but this is not related to the tension it will hold, as it should be assumed the material you are threading into meets or exceeds the tensile strength and therefore thread shear strength of the bolt threads. If not then your tension and subsequent torque values are governed by the material to be threaded into, not the bolt itself.

The reason the torque values for a fine threaded fastener tend to be higher, is because for a given bolt diameter, a fine thread has a larger minor diameter than a coarse thread (easy to see by looking at it). The tensile strength is determined by the minor diameter of a the bolt, as that is where failure will occur.

The finer thread pitch simply allows more radial distance to "fine tune" the tension on the bolt.
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So much wrong in this post... I dont have time to go through it right now. Explanations comming later if others dont beat me to it.
 
So is it unanamous that:
Since the earth is round and the altitudal differences surpass the equation of the active lunar location in which the tide rolls upon; that the frequencies of all the sounds together along with the geodetical vertical and horizontal planes across the globe; that make way for divisional proof that this thread is now.... officially... dead.:flipoff2:

Some things just wasn't meant to be Rocket Science...:shaking:
 
GCncsuHD said:
The head of the bolt has nothing at all to do with the tension you can apply to the bolt via torque.

Thread pitch does have to do with the applied tension per applied torque, but in many cases is deemed negligible for real life purposes, the variance in torque wrenches is at times larger than that.

Fine threaded bolts do have more "holding power" due to the fine thread pitch creating more surface area (stress area) to divide the stress along the threads, but this is not related to the tension it will hold, as it should be assumed the material you are threading into meets or exceeds the tensile strength and therefore thread shear strength of the bolt threads. If not then your tension and subsequent torque values are governed by the material to be threaded into, not the bolt itself.

The reason the torque values for a fine threaded fastener tend to be higher, is because for a given bolt diameter, a fine thread has a larger minor diameter than a coarse thread (easy to see by looking at it). The tensile strength is determined by the minor diameter of a the bolt, as that is where failure will occur.

The finer thread pitch simply allows more radial distance to "fine tune" the tension on the bolt.
Click to expand...
Falko said:
So much wrong in this post... I dont have time to go through it right now. Explanations comming later if others dont beat me to it.
Click to expand...

I'll just say that you completely missed my point. No shit that the head has nothing to do with the tension you CAN apply to it. Although that's only half-true b/c the bigger the head, the "easier" it is is to apply torque to the bolt.

I was simply asking about the trade-off between the torque you apply, and the likelihood of it slipping. Or really you just re-stated it in your last sentence. Finer thread allows more fine-tuning.
I'm thinking from a safety & natural un-winding standpoint, not tension and how much torque before sheer.
If I have a bolt w/ really coarse threads, I will be more likely to apply a higher torque so it is tighter - b/c once, or if, it begins to unwind, it will do so quickly... whereas a fine thread will have more surface drag for a longer period before it is "free" to spin.
 
RatLabGuy said:
I'll just say that you completely missed my point. No shit that the head has nothing to do with the tension you CAN apply to it. Although that's only half-true b/c the bigger the head, the "easier" it is is to apply torque to the bolt.

I was simply asking about the trade-off between the torque you apply, and the likelihood of it slipping. Or really you just re-stated it in your last sentence. Finer thread allows more fine-tuning.
I'm thinking from a safety & natural un-winding standpoint, not tension and how much torque before sheer.
If I have a bolt w/ really coarse threads, I will be more likely to apply a higher torque so it is tighter - b/c once, or if, it begins to unwind, it will do so quickly... whereas a fine thread will have more surface drag for a longer period before it is "free" to spin.
Click to expand...

It was not clear that your question was about the nut "slipping". You are right, I did miss your point. Your question read to me as if you were talking about the bolt stripping the threads out of the material it was threaded into.

Explain to me how the larger bolt head makes it easier to apply torque to the bolt, unless you are tightening it by hand? i.e. easier to grip. It doesn't matter if you have a 1/2" bolt head or a 1" bolt head, you will still apply the same force at the end of the wrench to have the same applied torque.

Yes, a fine thread will generally be more resistant to "slipping" as you called it. The more torque you apply, the more tension the bolt is under, thus the more friction between the nut and the bolt thread mating surfaces. But torque values are not generally specified for most applications in relation to retaining the nut to bolt friction, but rather for it's clamping force or tension. That is just a bonus. Generally the friction required to keep the bolt from slipping is reached well before the desired clamping force or tension is reached. This trailer ball instance is one instance where the clamping force is not all that important, but rather retention is, thus the torque that is basically 1/4 of the torque needed to reach the max clamping force of that fastener.
 
R Q said:
Put the hitch in the reciever sideways so you can put the pipe wrench and bar on it. Then stand on it and you'll have it.
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This is a cool idea that I wouldn't have thought of. I can't even put a number on the amount of times I've put the nut on with a 24" breaker bar and pulled as hard as I can. Being 6'4" and 275 being able to stand/jump on it would probably exceed any torque requirements. Sorry to beat the " Dead " thread. I am really busy, so I am always late to the party.
 
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