Bolt preload vs. transport screw torque
Bolt preload vs. transport screw torque
(OP)
I have found several calculations and calculators regarding bolt preload for flanges etc, but I think this is different from the torque/tensile regarding a "free" transport screw or similar e.g. where the underlaying plates is NOT supporting the bolt preload.
Can anyone advise on this subject, formulas, links etc.
Regards
Tommy
Can anyone advise on this subject, formulas, links etc.
Regards
Tommy





RE: Bolt preload vs. transport screw torque
I have heard of transport screws but not a free transport screw what is it? a sketch of what your talking about might help
desertfox
RE: Bolt preload vs. transport screw torque
If you have a weight hanging from the screw this is the bolt load. Then you have a nut transporting this screw upwards. Then the preload in the bolt is then only the weight, and the moment transferred to the nut comes from friction between nut and bolt... This must differ from when you have something to squeeze between bolt head and nut...
RE: Bolt preload vs. transport screw torque
Yes I think see what you mean, the nut is just run up the screw and supports the weight although the nut is not tightened up, so the weight can only transfer its load to the bolt via the nut.
The load in the bolt will only be the hanging weight and yes its different to tightening the nut hard up.
You need to check the threads on the bolt and nut for stripping.
desertfox
RE: Bolt preload vs. transport screw torque
http://en.wikipedia.org/wiki/Leadscrew
RE: Bolt preload vs. transport screw torque
If its a leadscrew you mean then you can try this calculator:-
http://www.tribology-abc.com/calculators/e4_6.htm
desertfox
RE: Bolt preload vs. transport screw torque
RE: Bolt preload vs. transport screw torque
RE: Bolt preload vs. transport screw torque
http://www.hexagon.de/rs/k.htm
RE: Bolt preload vs. transport screw torque
I think your talking about the torque applied to the nut to lift a component or weight if so trque is based on the pitch diameter of the thread.
look at this site:- http://
desertfox
RE: Bolt preload vs. transport screw torque
RE: Bolt preload vs. transport screw torque
Well I don't understand from your answer whether the link I gave you last is of any use, if it isn't of any use then put a sketch of your situation then we can see clearly what your trying to do instead of guessing.
desertfox