BOLTS 1

[elpa02]

Hello,

I would like to be adviced on two matters about bolts.

At first where can i find a table related with the alloweded torque load for each bolt dimension (e.g. M2,M4....)and with the strenght grades(3.6,12.9 etc).

There is a small pipe with internal thread at both ends.
At the one end it is bolted a bolt and at the other end it is installed a manometer.
The pipe is filled with oil.No leakages.If we start bolt the bolt the pressure shall be increased. How can i find the torque demand related with the pressure.
Can i start with : Torque =F*p/2 where F=the axial force
p=pace.

Thanks in advance

 

[borjame]

This sounds like a problem from college, if I tell you, will I be helping you cheat?
Anyway, the torques for threaded members can be found online, try google.com. You'll also need to know the nut/bolt materials, coating, and any lubricant present.
To calcualate the torque, you make your force triangle. The pressure from the fliud will be your vertical leg, the torque gets converted onto the horizontal, and friction acts along the hypotenuse. The angles in the triangle depend on thread pitch and size. As you torque the bolt, the reaction load from the threads creates the downward pressure on the oil/manometer.

 

[vonlueke]

elpa02: For information pertaining to your first question, try

http://euler9.tripod.com/fasteners/preload.html

and

http://euler9.tripod.com/bolt-database/

.

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