U Bolts

[Lutfi]

I have a vertical steel pipe that I want to fasten a horizontal member to it by using U-Bolt. The U-bolt will be tightened around the vertical pipe column and will run through the horizontal member. How much vertical force and how one go about computing it? Are their "cook book" type tables with such values?

The vertical pipe is 2.5-inch diameter. The U-bolt will be stainless steel, 0.5-inch diameter.

Thanks for your help in advance.

 

[Trussdoc]

Doesn't sound like a real good connection to me...it relies only on friction ( between the bolt and pipe, and the horizontal member and pipe )This could be affected by temperature and environmental conditions, especially if dissimilar materials are used. Not something I would stand under.

 

[Lutfi]

This will be a small stand to support a camera on a commmunications tower. The total vertical load is 150 pounds and will be carried by two U-bolts.

 

[Ron]

Resistance will be the tension in the bolt times the unit coefficient of friction between the bolt and the column.

 

[Lutfi]

Ron,

That is exactly what I think. I need to specify the torque (tensioning of the U-bolt).

 

[dlew]

Lufti,

There are formulas and tables to calculate the torque required to get a given tension in the bolt.

For non-lubricated high strength bolts, 1/2" in diameter, an old AISC publication shows hat a torque of 90 ft-lbs is required to produce a tension in the bolt of 10,850 pounds.
Torque and tension should vary linearly except for small values.

Hope this help

AEF