Bolt Screw Lift Device 2

[facca]

How do I calculate the vertical lift capacity of a 1-inch dia. 304 S.Stl. UNC bolt?
The nut & bolt act as a lifting device and will be torqued by hand. The action of the pitch will raise the load. At what point should we worry about load binding?

From the mechanical forum, I have learned that without adequate lubrication, the threads will likely gall and bind. That aside, I need a reference or equation to determine the possible lift load.
Thanks

 

[SlideRuleEra]

One of the basic six simple machines. See the bottom of this page

http://www.uark.edu/depts/aeedhp/agscience/simpmach.htm

http://www.SlideRuleEra.net

 

[rb1957]

i'd use a bolt preload formula ...

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

to relate torque to bolt load.

i'd have thought that the bolt would be able to lift it's tensile strength, in your case in excess of 80,000 lbs. the problem you might run into is the torque to overcome static friction ...

 

[sundale]

Most helical (and push) piers used in underpinning repairs use a lift head with two bolts in tension that are used to "pull" the foundation up. You might go to Atlas or Chance and see what kind up setup their lift heads imply in regards to axial lift (tension) capacity and a hand cranked nut on an all thread rod.