I'm trying to find a "rough" / "general" formula for the tensile force caused by a bolt torqued to a specific value.
All I have found so far are formulas a whole page wide, and over-simplified calculators; nothing in between. If anybody knows a rough formula where I can input torque ft-lbs, coefficient of friction, and TPI, that would be great. I know it would not be exact, but whatever; I just need "a number" to go with.
But that is not my main purpose here. My question is: how is it possible to calculate the tensile force without inputting the thread pitch?
For example the formula here.
or the calculator here.
In the above calculator I input:
456 in-lbs torque
.5" diameter
.18 coefficient of friction
and it returns 5067 lbs of tension.
How can it know that without knowing the thread pitch? The 1/2" bolts in question are coarse thread, but if they were fine thread, they would create a higher tension for a given torque, wouldn't they? The calculator doesn't know if I'm talking coarse thread or fine thread, so what gives?
All I have found so far are formulas a whole page wide, and over-simplified calculators; nothing in between. If anybody knows a rough formula where I can input torque ft-lbs, coefficient of friction, and TPI, that would be great. I know it would not be exact, but whatever; I just need "a number" to go with.
But that is not my main purpose here. My question is: how is it possible to calculate the tensile force without inputting the thread pitch?
For example the formula here.
or the calculator here.
In the above calculator I input:
456 in-lbs torque
.5" diameter
.18 coefficient of friction
and it returns 5067 lbs of tension.
How can it know that without knowing the thread pitch? The 1/2" bolts in question are coarse thread, but if they were fine thread, they would create a higher tension for a given torque, wouldn't they? The calculator doesn't know if I'm talking coarse thread or fine thread, so what gives?